Date   
Re: DEAD 9845 power supplies

Lee A. White
 

Some comments regarding HP documentation practices and some comments on my approach to this PSU repair task.
 
If you were an engineer at HP changing something on a part, but the part was both forward and backward compatible with the same part prior to the change and if it was also forward and backward compatible with any higher level assemblies this part was used in, then the part number you assigned would remain unchanged and the revision level would be increased to the next letter. This means that we should be able to swap out good boards of any revision level within any revision level of the same power supply assembly part number and they should all still work OK. The 9845 A , B, and T all used the same part number PSU assembly and are thus interchangeable between these models and any combination of boards with the same part number should work together regardless of rev letter. From that perspective, swapping PSUs to troubleshoot mainframe issues and swapping boards to trouble shoot a PSU is a valid approach. It does have some potential risks however in that a defective mainframe may blow a good PSU assembly or a defective power supply may damage a good mainframe or a defective PSU board installed in a good PSU may damage other PSU boards and likewise a good board that has been installed into a defective PSU may also be blown. I have read of one case where this did happen to an EE attempting a PSU repair by board swapping. I have also been told that one person succeeded with this approach. For this reason, where possible and to the extent possible I will be attempting to test and repair individual boards prior to attempting to assemble a working power supply from them.
 
In many cases there are failure modes that are far more prevalent and key components who's failure is far more likely. I will be attempting to test for these failure modes and to determine if those suspect components are good or not prior to powering up the board. When I do power up a board, where possible and to the extent possible I will be attempting to use a Variac to bring up input voltages gradually while monitoring the circuits under test. I hope to detect component and circuit failures  prior to doing any further damage.
 
Since I have three PSUs I will also be attempting to make unpowered measurement at various points on the boards to compare the boards to each other. Hopefully, differences in these measurements will help establish the location and type of failure present. Since the failures observed to date on these three PSUs are different, measurements which are the same for different PSUs and their boards would tend to indicate good components and good circuits up to that point. These measurement can also be used by others in their troubleshooting efforts to quickly and safely see if their boards are performing similarly to known good or defective boards.
 
If those of you with defective power supplies could work along in parallel we might be able to establish a useful database of tests and expected results for various rev level boards and also likely failure causes for differing test results. 
 
 
Lee White

Sent: Friday, September 21, 2018 6:20 PM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

One more comment about all this PSU stuff. As HP went through the many revision levels on the PSU boards they apparently did a relayout of the board at some point rerouting some traces and producing new PCB board fab artwork and that triggered a renumbering of the components from a component designator part number stand point. So, even though a portion of a circuit may be unchanged and the components may all be the same identical parts, they will have all new component designator numbers. A case in point is the two large filter caps on the main DC buss. Early rev boards are C 17 and C 18, and later boards have them as C 14 and C 19. Likewise the bridge rectifiers are C 15 to C 18 originally and now are CR 27 to CR 30. I see confusion coming! We need to be clear what rev schematic we are discussing.
 
Lee

Sent: Friday, September 21, 2018 6:10 PM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Guys
 
I am going to tell all as I go along investigating the PSU problems in the hope that some one will speak up and prevent a big mistake. I would rather look stupid and stay alive. I also hope to learn a bit from everyone's comments. Even better, I hope the exhaustive comments will help the uninitiated to safely and successfully trouble shoot their supplies. So I hereby invite all comments - the more the better. And please excuse the random wanderings.
 
As a start to safety I intend to power the PSU and the test equipment in use from 115VAC single phase power lines with separate GFCI (Ground Fault Circuit Interupter) breakers in their respective power lines for protection against power to neutral and power to ground electrocution. It is my understanding that these breakers compare line to neutral current and trip any time these currents are different by more than a preset value - about 35 ma if I recall correctly. I also understand that this will not protect against electrocution if I get across any charge storage devices like capacitors, and that electrocution across a capacitor containing circuit is still a real possibility that is made all the more possible by the energy storage capacity of those two big electrolytics charged up to full DC buss voltage - 160 VDC each - 320 VDC total - or possibly even more if there is a circuit fault. A fully rectified 230 VAC line can put out a filtered DC of about 320 volts - if I recall correctly. Sounds pretty fatal to me.
 
Capacitors can hold charge for long periods of time and can be fatal after power has been of for a while. To be safe, you need to discharge these caps every time you turn off the power to the supply or you risk getting zapped. Been there - done that - and it hurts! It can be worse. I have made a capacitor discharge tool out of a 100 ohm 15 watt wire wound resistor. The resistor leads are bent to fit into the voltage test holes in the PSU metal cover and are insulated with two layers of heat shrink. The body of the resistor is insulated with a split piece of thick rubber hose wrapped around the resistor and secured in place. I am well protected from electrical shock and from heat or explosion of the resistor itself. May seem like overkill but I once burned a slot in my thumb putting a resistor across a big cap to discharge it - not going there again!
 
I have checked out the power line to PSU circuitry and found no faults there. The input power line goes through a single fuse on the back plane casting so be careful if you are using center tapped 230 VAC with the center tap grounded (as is the cse in the USA) as both sides of the line are hot relative to ground and both are not interrupted by the line fuse when it blows. The 9845 has a voltage selector switch that can be set for 115 or 230 VAC. In the lower voltage position this switch wires the 115 VAC fans in parallel across the power line. Likewise, the two primary windings of the power supply start up power circuit transformer (T2) are also wired in parallel for low voltage input. With the switch in the high voltage position, the fans are wired in series as are the power supply start up power transformer primary windings. The input to the primary power rectifiers in the PSU is across pins 1 and 2 of the power supply input power connector J0 and the main power rectifier seems to be powered by full line voltage. There are also components in the line filter that also appear across the power lines. So with the system disconnected from the input power line when you turn the mainframe switch on and ring out the input power circuit you will see a load across the power line from the fans etc even with the PSU removed from the main frame. Also, looking in from the power cord plug, the ground and neutral sides of the input line will show continuity even with a blown line fuse as the fuse only disables the hot line itself. Ringing out the power connector from the mainframe to the power supply itself will give different results depending on which position the voltage selector is in.
 
The next issue in getting ready to bench test the PSU is getting or making an isolation transformer - mine is at my other house 1,100 miles away - so I need to come up with something to be safe.
 
I have a fairly large transformer removed from a CNC system - 1.5 KVA with 240/480 VAC primary and 79 VAC secondary. The primary is two isolated windings that can be wired in series for high voltage or parallel for low voltage. There is a separate single winding secondary.
 
Worst case 1.5 KVA at 480 volts through windings in series would be 3.13 amps, so each of the primaries should be able to withstand 3 amps. If I wire one of the primaries as the primary across the 120 VAC power line and wire the second primary winding as the secondary, I should be able to put 120 vac into it and get 120 VAC out of it at 3 amps. That should be enough to run the PSU separately and also the entire 9845 computer. The normal secondary winding will be generating a voltage but if I leave it open and caped off for safety, that should not be a problem. Wired this way this transformer should provide the safety isolation I require.
 
Anyone see a problem with this? Am I good to go?
 
Off topic extra credit question:
 
I also have another much larger 3 phase transformer - three separate primary/secondary winding sets, each set wound on a different leg of a common 3 leg magnetic core  (a figure eight made of stacked E and Bar laminations). This transformer has a nominal 240 VAC 3Ph primary with lots of taps on the primary to adjust for various input line voltages, and a 120 VAC 3 ph secondary.
 
I would not have thought it would be possible to make a three phase to three phase transformer using a single common shared magnetic core. All of the three phase transformers I have encountered previously were three separate single phase transformers wired across the three phase lines in a classic Wye or Delta configuration. They did not share a magnetic circuit. If some one has a simple explanation as to what the fluxes are doing in each leg and how this transformer works, I would like to hear it! In particular, how is it that the coils on one leg seem to operate independently of the fluxes generated in the other legs? Some how they must cancel but how when the voltages are 120 degrees out of phase and one current can be increasing when the other is decreasing? Interesting!
 
In any case, this is a much heavier transformer and would make a better isolation transformer if it can be used for such. I would think I could use just one set of windings leaving all the rest open circuit. Then it should function as a normal single phase transformer. Also, I should be able to use two coils wired such that the flux passes through one then the other and then series the coils with polarity observed so they add voltages. Would I get twice the voltage because the two secondaries are series wired or would I get four times the voltage because the magnetic flux is doubled too? What happens if I wire the two outside coils with the same polarity vs reversed? Would the flux then go up from each outside leg with an active winding and turn toward the center leg, then go down through the center leg, and then split and return to the two outside legs? Or, does the flux from any leg divide equally and go through each other leg simultaneously? Does the center leg act as a magnetic short and isolate one coil set from another on a different leg? Clearly I don't have much experience with the details of magnetic fields and cores and coils and transformers!
 
Bottom line - Question is, can I make a larger and greater current capacity isolation transformer out of this three phase transformer, and if so how best to do it?
 
I also want to put a variac on the input side to adjust output voltages and allow starting testing at reduced input voltages. Any problems with this idea that I need to be aware of - other than the obvious one that variacs share one lead of the primary and the secondary windings, so they are not input to output isolated?
 
Finally, I will be working on a wooden work bench while sitting on a wooden chair with my feet up on a wooden foot rest. There is only one metallic ground within reach and it is up high on a wall in the form of a grounded conduit to a 230 VAC power outlet. No reason to be reaching for that. The only other grounding issue arises from the test equipment itself. The ground side of oscilloscope probes is normally grounded, as are the cases of many instruments. I have to do some thinking about those potential ground paths as floating them can cause another problem. I am hoping the GFCI will provide adequate protection. If not - observing the one hand only rule should prevent a disaster. Problem is - it is easy to forget - especially when something falls - so securing everything before you power up is very wise. 
 
Well, that is where I am now.
 
Next, I need an explanation of what that circuit in the upper right hand corner of the schematic for the 66582 board does. I am guessing it is a regulator for the DC link supply and that the triac Q12 is doing the regulation but I am not an EE so how would I know!
 
 
Lee 
 
PS: I have a redrawn and cleaned up version of the 66582 board schematic made from the schematic from Ansgar's site that I down loaded from a Canadian's blog. It is for a later rev board. I will try to attach it.

Sent: Friday, September 21, 2018 1:43 PM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Guys
 
The only instrument I have to measure capacitors is an ancient whetstone bridge with capacitance settings and an "eye tube" for the indicator. I am sure the reference capacitors in this instrument are almost certainly dead or have drifted considerably.
 
So, what is a good reasonable affordable instrument for measuring capacitors?
 
Can you test them in-circuit or do you usually need to pull up one or both leads?
 
If you have to pull them to test them - wouldn't it make sense to just replace them with new ones?
 
 
NEXT ISSUE:
 
I have three PSU and each of the 66582 boars has different voltage test results when in a complete PSU assembly and powered up. In particular, the voltages on the two main filter caps - C17 and C 18. One PSU has 0 VDC on both, one had ) VDC on one, and one hast the correct voltage on both. I am thinking the best approach is to isolate this board, power it up, and trace down the faults in this section, and also test out the start up power supply section. Anyone see any difficulty in doing this? Any chance of blowing something on the board doing so? I have already made measurements of the transformers, fuses, and bridges - in circuit - and can not detect any differences between the three boards.
 
 
Lee 

Sent: Monday, September 10, 2018 8:54 AM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Hi Lee,

I don't know about the specifics of the electrolytics used in the 9845 and I can't find a photo online, but there's no general "supposed to" rule when it comes to capacitor case grounding. Most of today's radial electrolytics have shrink-wrapped cases to insulate them. The fact that the grounding is intermittent is certainly troubling.

What you really want to know about a capacitor (any capacitor) is its actual capacitance and its ESR (equivalent series resistance). Old electrolytics that start to dry out and die lose capacitance and their ESR increases. Both of these parameter changes degrade the cap's ability to do its intended job. There are techniques for attempting to reform a capacitor. I don't recommend them. They need replacing.

The old multi-capacitor electrolytic cans intentionally used the can as a common ground. These were common in tube radios of the 1950s, for example. They're also common in electric guitar amplifiers of the era. I've seen many YouTube videos by The Guitologist and Mr Carlson, both restorers of old tube gear, who routinely replace these multi-cap cans with multiple, modern electrolytics. But they always measure first.

You have to measure these two values (capacitance and ESR) to really know about a capacitor's health. In the old days, when you and I worked for HP, you spent lots of money to buy an instrument to measure these values. Today, you either use the capacitance range on your expensive DMM (assuming you have one) or you spend $11.95 on eBay for a general-purpose component tester that can test capacitors, resistors, coils, bipolar transistors, FETs, and diodes:

https://www.ebay.com/itm/12864-Mega328-ESR-Transistor-Resistor-Diode-Capacitor-Mosfet-Tester-w-Test-hook/222084192100?hash=item33b53fd764:g:ZvEAAOSwlGtbV01I

I have one of these testers. They work surprisingly well for the money. A simple on-board microcontroller does all the hard work including driving the tester's LCD (which looks like it was salvaged from an old mobile phone). If you're going to be looking at all of those caps (and other old parts) in your three 9845 PSUs, you might consider getting one.


--Steve



On 9/9/2018 11:26 PM, Lee A. White wrote:
Newbie Question - are the electrolytic capacitors with two leads coming out of the same end of the can supposed to have one lead that is grounded to the can, or are they both supposed to be isolated electrically? I seem to have some with leads that that are both isolated and some that are not. Is one lead shorting to the can a sign they are bad? Worse yet, seems to be intermittent on some of them. I am not ready to start pulling components quite yet so I can't just look to see how they are built. I do know that the caps with one axial lead coming out of each end often do have one lead that is grounded to the can.
 
Lee
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

-- 
Steve Leibson

Phone (Cell): 408-910-5992
Phone (Home): 408-292-4930


Please feel free to link to me on LinkedIn


History site: www.hp9825.com

Re: DEAD 9845 power supplies

Lee A. White
 

One more comment about all this PSU stuff. As HP went through the many revision levels on the PSU boards they apparently did a relayout of the board at some point rerouting some traces and producing new PCB board fab artwork and that triggered a renumbering of the components from a component designator part number stand point. So, even though a portion of a circuit may be unchanged and the components may all be the same identical parts, they will have all new component designator numbers. A case in point is the two large filter caps on the main DC buss. Early rev boards are C 17 and C 18, and later boards have them as C 14 and C 19. Likewise the bridge rectifiers are C 15 to C 18 originally and now are CR 27 to CR 30. I see confusion coming! We need to be clear what rev schematic we are discussing.
 
Lee

Sent: Friday, September 21, 2018 6:10 PM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Guys
 
I am going to tell all as I go along investigating the PSU problems in the hope that some one will speak up and prevent a big mistake. I would rather look stupid and stay alive. I also hope to learn a bit from everyone's comments. Even better, I hope the exhaustive comments will help the uninitiated to safely and successfully trouble shoot their supplies. So I hereby invite all comments - the more the better. And please excuse the random wanderings.
 
As a start to safety I intend to power the PSU and the test equipment in use from 115VAC single phase power lines with separate GFCI (Ground Fault Circuit Interupter) breakers in their respective power lines for protection against power to neutral and power to ground electrocution. It is my understanding that these breakers compare line to neutral current and trip any time these currents are different by more than a preset value - about 35 ma if I recall correctly. I also understand that this will not protect against electrocution if I get across any charge storage devices like capacitors, and that electrocution across a capacitor containing circuit is still a real possibility that is made all the more possible by the energy storage capacity of those two big electrolytics charged up to full DC buss voltage - 160 VDC each - 320 VDC total - or possibly even more if there is a circuit fault. A fully rectified 230 VAC line can put out a filtered DC of about 320 volts - if I recall correctly. Sounds pretty fatal to me.
 
Capacitors can hold charge for long periods of time and can be fatal after power has been of for a while. To be safe, you need to discharge these caps every time you turn off the power to the supply or you risk getting zapped. Been there - done that - and it hurts! It can be worse. I have made a capacitor discharge tool out of a 100 ohm 15 watt wire wound resistor. The resistor leads are bent to fit into the voltage test holes in the PSU metal cover and are insulated with two layers of heat shrink. The body of the resistor is insulated with a split piece of thick rubber hose wrapped around the resistor and secured in place. I am well protected from electrical shock and from heat or explosion of the resistor itself. May seem like overkill but I once burned a slot in my thumb putting a resistor across a big cap to discharge it - not going there again!
 
I have checked out the power line to PSU circuitry and found no faults there. The input power line goes through a single fuse on the back plane casting so be careful if you are using center tapped 230 VAC with the center tap grounded (as is the cse in the USA) as both sides of the line are hot relative to ground and both are not interrupted by the line fuse when it blows. The 9845 has a voltage selector switch that can be set for 115 or 230 VAC. In the lower voltage position this switch wires the 115 VAC fans in parallel across the power line. Likewise, the two primary windings of the power supply start up power circuit transformer (T2) are also wired in parallel for low voltage input. With the switch in the high voltage position, the fans are wired in series as are the power supply start up power transformer primary windings. The input to the primary power rectifiers in the PSU is across pins 1 and 2 of the power supply input power connector J0 and the main power rectifier seems to be powered by full line voltage. There are also components in the line filter that also appear across the power lines. So with the system disconnected from the input power line when you turn the mainframe switch on and ring out the input power circuit you will see a load across the power line from the fans etc even with the PSU removed from the main frame. Also, looking in from the power cord plug, the ground and neutral sides of the input line will show continuity even with a blown line fuse as the fuse only disables the hot line itself. Ringing out the power connector from the mainframe to the power supply itself will give different results depending on which position the voltage selector is in.
 
The next issue in getting ready to bench test the PSU is getting or making an isolation transformer - mine is at my other house 1,100 miles away - so I need to come up with something to be safe.
 
I have a fairly large transformer removed from a CNC system - 1.5 KVA with 240/480 VAC primary and 79 VAC secondary. The primary is two isolated windings that can be wired in series for high voltage or parallel for low voltage. There is a separate single winding secondary.
 
Worst case 1.5 KVA at 480 volts through windings in series would be 3.13 amps, so each of the primaries should be able to withstand 3 amps. If I wire one of the primaries as the primary across the 120 VAC power line and wire the second primary winding as the secondary, I should be able to put 120 vac into it and get 120 VAC out of it at 3 amps. That should be enough to run the PSU separately and also the entire 9845 computer. The normal secondary winding will be generating a voltage but if I leave it open and caped off for safety, that should not be a problem. Wired this way this transformer should provide the safety isolation I require.
 
Anyone see a problem with this? Am I good to go?
 
Off topic extra credit question:
 
I also have another much larger 3 phase transformer - three separate primary/secondary winding sets, each set wound on a different leg of a common 3 leg magnetic core  (a figure eight made of stacked E and Bar laminations). This transformer has a nominal 240 VAC 3Ph primary with lots of taps on the primary to adjust for various input line voltages, and a 120 VAC 3 ph secondary.
 
I would not have thought it would be possible to make a three phase to three phase transformer using a single common shared magnetic core. All of the three phase transformers I have encountered previously were three separate single phase transformers wired across the three phase lines in a classic Wye or Delta configuration. They did not share a magnetic circuit. If some one has a simple explanation as to what the fluxes are doing in each leg and how this transformer works, I would like to hear it! In particular, how is it that the coils on one leg seem to operate independently of the fluxes generated in the other legs? Some how they must cancel but how when the voltages are 120 degrees out of phase and one current can be increasing when the other is decreasing? Interesting!
 
In any case, this is a much heavier transformer and would make a better isolation transformer if it can be used for such. I would think I could use just one set of windings leaving all the rest open circuit. Then it should function as a normal single phase transformer. Also, I should be able to use two coils wired such that the flux passes through one then the other and then series the coils with polarity observed so they add voltages. Would I get twice the voltage because the two secondaries are series wired or would I get four times the voltage because the magnetic flux is doubled too? What happens if I wire the two outside coils with the same polarity vs reversed? Would the flux then go up from each outside leg with an active winding and turn toward the center leg, then go down through the center leg, and then split and return to the two outside legs? Or, does the flux from any leg divide equally and go through each other leg simultaneously? Does the center leg act as a magnetic short and isolate one coil set from another on a different leg? Clearly I don't have much experience with the details of magnetic fields and cores and coils and transformers!
 
Bottom line - Question is, can I make a larger and greater current capacity isolation transformer out of this three phase transformer, and if so how best to do it?
 
I also want to put a variac on the input side to adjust output voltages and allow starting testing at reduced input voltages. Any problems with this idea that I need to be aware of - other than the obvious one that variacs share one lead of the primary and the secondary windings, so they are not input to output isolated?
 
Finally, I will be working on a wooden work bench while sitting on a wooden chair with my feet up on a wooden foot rest. There is only one metallic ground within reach and it is up high on a wall in the form of a grounded conduit to a 230 VAC power outlet. No reason to be reaching for that. The only other grounding issue arises from the test equipment itself. The ground side of oscilloscope probes is normally grounded, as are the cases of many instruments. I have to do some thinking about those potential ground paths as floating them can cause another problem. I am hoping the GFCI will provide adequate protection. If not - observing the one hand only rule should prevent a disaster. Problem is - it is easy to forget - especially when something falls - so securing everything before you power up is very wise. 
 
Well, that is where I am now.
 
Next, I need an explanation of what that circuit in the upper right hand corner of the schematic for the 66582 board does. I am guessing it is a regulator for the DC link supply and that the triac Q12 is doing the regulation but I am not an EE so how would I know!
 
 
Lee 
 
PS: I have a redrawn and cleaned up version of the 66582 board schematic made from the schematic from Ansgar's site that I down loaded from a Canadian's blog. It is for a later rev board. I will try to attach it.

Sent: Friday, September 21, 2018 1:43 PM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Guys
 
The only instrument I have to measure capacitors is an ancient whetstone bridge with capacitance settings and an "eye tube" for the indicator. I am sure the reference capacitors in this instrument are almost certainly dead or have drifted considerably.
 
So, what is a good reasonable affordable instrument for measuring capacitors?
 
Can you test them in-circuit or do you usually need to pull up one or both leads?
 
If you have to pull them to test them - wouldn't it make sense to just replace them with new ones?
 
 
NEXT ISSUE:
 
I have three PSU and each of the 66582 boars has different voltage test results when in a complete PSU assembly and powered up. In particular, the voltages on the two main filter caps - C17 and C 18. One PSU has 0 VDC on both, one had ) VDC on one, and one hast the correct voltage on both. I am thinking the best approach is to isolate this board, power it up, and trace down the faults in this section, and also test out the start up power supply section. Anyone see any difficulty in doing this? Any chance of blowing something on the board doing so? I have already made measurements of the transformers, fuses, and bridges - in circuit - and can not detect any differences between the three boards.
 
 
Lee 

Sent: Monday, September 10, 2018 8:54 AM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Hi Lee,

I don't know about the specifics of the electrolytics used in the 9845 and I can't find a photo online, but there's no general "supposed to" rule when it comes to capacitor case grounding. Most of today's radial electrolytics have shrink-wrapped cases to insulate them. The fact that the grounding is intermittent is certainly troubling.

What you really want to know about a capacitor (any capacitor) is its actual capacitance and its ESR (equivalent series resistance). Old electrolytics that start to dry out and die lose capacitance and their ESR increases. Both of these parameter changes degrade the cap's ability to do its intended job. There are techniques for attempting to reform a capacitor. I don't recommend them. They need replacing.

The old multi-capacitor electrolytic cans intentionally used the can as a common ground. These were common in tube radios of the 1950s, for example. They're also common in electric guitar amplifiers of the era. I've seen many YouTube videos by The Guitologist and Mr Carlson, both restorers of old tube gear, who routinely replace these multi-cap cans with multiple, modern electrolytics. But they always measure first.

You have to measure these two values (capacitance and ESR) to really know about a capacitor's health. In the old days, when you and I worked for HP, you spent lots of money to buy an instrument to measure these values. Today, you either use the capacitance range on your expensive DMM (assuming you have one) or you spend $11.95 on eBay for a general-purpose component tester that can test capacitors, resistors, coils, bipolar transistors, FETs, and diodes:

https://www.ebay.com/itm/12864-Mega328-ESR-Transistor-Resistor-Diode-Capacitor-Mosfet-Tester-w-Test-hook/222084192100?hash=item33b53fd764:g:ZvEAAOSwlGtbV01I

I have one of these testers. They work surprisingly well for the money. A simple on-board microcontroller does all the hard work including driving the tester's LCD (which looks like it was salvaged from an old mobile phone). If you're going to be looking at all of those caps (and other old parts) in your three 9845 PSUs, you might consider getting one.


--Steve



On 9/9/2018 11:26 PM, Lee A. White wrote:
Newbie Question - are the electrolytic capacitors with two leads coming out of the same end of the can supposed to have one lead that is grounded to the can, or are they both supposed to be isolated electrically? I seem to have some with leads that that are both isolated and some that are not. Is one lead shorting to the can a sign they are bad? Worse yet, seems to be intermittent on some of them. I am not ready to start pulling components quite yet so I can't just look to see how they are built. I do know that the caps with one axial lead coming out of each end often do have one lead that is grounded to the can.
 
Lee
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

-- 
Steve Leibson

Phone (Cell): 408-910-5992
Phone (Home): 408-292-4930


Please feel free to link to me on LinkedIn


History site: www.hp9825.com

Re: DEAD 9845 power supplies

Lee A. White
 

Guys
 
I am going to tell all as I go along investigating the PSU problems in the hope that some one will speak up and prevent a big mistake. I would rather look stupid and stay alive. I also hope to learn a bit from everyone's comments. Even better, I hope the exhaustive comments will help the uninitiated to safely and successfully trouble shoot their supplies. So I hereby invite all comments - the more the better. And please excuse the random wanderings.
 
As a start to safety I intend to power the PSU and the test equipment in use from 115VAC single phase power lines with separate GFCI (Ground Fault Circuit Interupter) breakers in their respective power lines for protection against power to neutral and power to ground electrocution. It is my understanding that these breakers compare line to neutral current and trip any time these currents are different by more than a preset value - about 35 ma if I recall correctly. I also understand that this will not protect against electrocution if I get across any charge storage devices like capacitors, and that electrocution across a capacitor containing circuit is still a real possibility that is made all the more possible by the energy storage capacity of those two big electrolytics charged up to full DC buss voltage - 160 VDC each - 320 VDC total - or possibly even more if there is a circuit fault. A fully rectified 230 VAC line can put out a filtered DC of about 320 volts - if I recall correctly. Sounds pretty fatal to me.
 
Capacitors can hold charge for long periods of time and can be fatal after power has been of for a while. To be safe, you need to discharge these caps every time you turn off the power to the supply or you risk getting zapped. Been there - done that - and it hurts! It can be worse. I have made a capacitor discharge tool out of a 100 ohm 15 watt wire wound resistor. The resistor leads are bent to fit into the voltage test holes in the PSU metal cover and are insulated with two layers of heat shrink. The body of the resistor is insulated with a split piece of thick rubber hose wrapped around the resistor and secured in place. I am well protected from electrical shock and from heat or explosion of the resistor itself. May seem like overkill but I once burned a slot in my thumb putting a resistor across a big cap to discharge it - not going there again!
 
I have checked out the power line to PSU circuitry and found no faults there. The input power line goes through a single fuse on the back plane casting so be careful if you are using center tapped 230 VAC with the center tap grounded (as is the cse in the USA) as both sides of the line are hot relative to ground and both are not interrupted by the line fuse when it blows. The 9845 has a voltage selector switch that can be set for 115 or 230 VAC. In the lower voltage position this switch wires the 115 VAC fans in parallel across the power line. Likewise, the two primary windings of the power supply start up power circuit transformer (T2) are also wired in parallel for low voltage input. With the switch in the high voltage position, the fans are wired in series as are the power supply start up power transformer primary windings. The input to the primary power rectifiers in the PSU is across pins 1 and 2 of the power supply input power connector J0 and the main power rectifier seems to be powered by full line voltage. There are also components in the line filter that also appear across the power lines. So with the system disconnected from the input power line when you turn the mainframe switch on and ring out the input power circuit you will see a load across the power line from the fans etc even with the PSU removed from the main frame. Also, looking in from the power cord plug, the ground and neutral sides of the input line will show continuity even with a blown line fuse as the fuse only disables the hot line itself. Ringing out the power connector from the mainframe to the power supply itself will give different results depending on which position the voltage selector is in.
 
The next issue in getting ready to bench test the PSU is getting or making an isolation transformer - mine is at my other house 1,100 miles away - so I need to come up with something to be safe.
 
I have a fairly large transformer removed from a CNC system - 1.5 KVA with 240/480 VAC primary and 79 VAC secondary. The primary is two isolated windings that can be wired in series for high voltage or parallel for low voltage. There is a separate single winding secondary.
 
Worst case 1.5 KVA at 480 volts through windings in series would be 3.13 amps, so each of the primaries should be able to withstand 3 amps. If I wire one of the primaries as the primary across the 120 VAC power line and wire the second primary winding as the secondary, I should be able to put 120 vac into it and get 120 VAC out of it at 3 amps. That should be enough to run the PSU separately and also the entire 9845 computer. The normal secondary winding will be generating a voltage but if I leave it open and caped off for safety, that should not be a problem. Wired this way this transformer should provide the safety isolation I require.
 
Anyone see a problem with this? Am I good to go?
 
Off topic extra credit question:
 
I also have another much larger 3 phase transformer - three separate primary/secondary winding sets, each set wound on a different leg of a common 3 leg magnetic core  (a figure eight made of stacked E and Bar laminations). This transformer has a nominal 240 VAC 3Ph primary with lots of taps on the primary to adjust for various input line voltages, and a 120 VAC 3 ph secondary.
 
I would not have thought it would be possible to make a three phase to three phase transformer using a single common shared magnetic core. All of the three phase transformers I have encountered previously were three separate single phase transformers wired across the three phase lines in a classic Wye or Delta configuration. They did not share a magnetic circuit. If some one has a simple explanation as to what the fluxes are doing in each leg and how this transformer works, I would like to hear it! In particular, how is it that the coils on one leg seem to operate independently of the fluxes generated in the other legs? Some how they must cancel but how when the voltages are 120 degrees out of phase and one current can be increasing when the other is decreasing? Interesting!
 
In any case, this is a much heavier transformer and would make a better isolation transformer if it can be used for such. I would think I could use just one set of windings leaving all the rest open circuit. Then it should function as a normal single phase transformer. Also, I should be able to use two coils wired such that the flux passes through one then the other and then series the coils with polarity observed so they add voltages. Would I get twice the voltage because the two secondaries are series wired or would I get four times the voltage because the magnetic flux is doubled too? What happens if I wire the two outside coils with the same polarity vs reversed? Would the flux then go up from each outside leg with an active winding and turn toward the center leg, then go down through the center leg, and then split and return to the two outside legs? Or, does the flux from any leg divide equally and go through each other leg simultaneously? Does the center leg act as a magnetic short and isolate one coil set from another on a different leg? Clearly I don't have much experience with the details of magnetic fields and cores and coils and transformers!
 
Bottom line - Question is, can I make a larger and greater current capacity isolation transformer out of this three phase transformer, and if so how best to do it?
 
I also want to put a variac on the input side to adjust output voltages and allow starting testing at reduced input voltages. Any problems with this idea that I need to be aware of - other than the obvious one that variacs share one lead of the primary and the secondary windings, so they are not input to output isolated?
 
Finally, I will be working on a wooden work bench while sitting on a wooden chair with my feet up on a wooden foot rest. There is only one metallic ground within reach and it is up high on a wall in the form of a grounded conduit to a 230 VAC power outlet. No reason to be reaching for that. The only other grounding issue arises from the test equipment itself. The ground side of oscilloscope probes is normally grounded, as are the cases of many instruments. I have to do some thinking about those potential ground paths as floating them can cause another problem. I am hoping the GFCI will provide adequate protection. If not - observing the one hand only rule should prevent a disaster. Problem is - it is easy to forget - especially when something falls - so securing everything before you power up is very wise. 
 
Well, that is where I am now.
 
Next, I need an explanation of what that circuit in the upper right hand corner of the schematic for the 66582 board does. I am guessing it is a regulator for the DC link supply and that the triac Q12 is doing the regulation but I am not an EE so how would I know!
 
 
Lee 
 
PS: I have a redrawn and cleaned up version of the 66582 board schematic made from the schematic from Ansgar's site that I down loaded from a Canadian's blog. It is for a later rev board. I will try to attach it.

Sent: Friday, September 21, 2018 1:43 PM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Guys
 
The only instrument I have to measure capacitors is an ancient whetstone bridge with capacitance settings and an "eye tube" for the indicator. I am sure the reference capacitors in this instrument are almost certainly dead or have drifted considerably.
 
So, what is a good reasonable affordable instrument for measuring capacitors?
 
Can you test them in-circuit or do you usually need to pull up one or both leads?
 
If you have to pull them to test them - wouldn't it make sense to just replace them with new ones?
 
 
NEXT ISSUE:
 
I have three PSU and each of the 66582 boars has different voltage test results when in a complete PSU assembly and powered up. In particular, the voltages on the two main filter caps - C17 and C 18. One PSU has 0 VDC on both, one had ) VDC on one, and one hast the correct voltage on both. I am thinking the best approach is to isolate this board, power it up, and trace down the faults in this section, and also test out the start up power supply section. Anyone see any difficulty in doing this? Any chance of blowing something on the board doing so? I have already made measurements of the transformers, fuses, and bridges - in circuit - and can not detect any differences between the three boards.
 
 
Lee 

Sent: Monday, September 10, 2018 8:54 AM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Hi Lee,

I don't know about the specifics of the electrolytics used in the 9845 and I can't find a photo online, but there's no general "supposed to" rule when it comes to capacitor case grounding. Most of today's radial electrolytics have shrink-wrapped cases to insulate them. The fact that the grounding is intermittent is certainly troubling.

What you really want to know about a capacitor (any capacitor) is its actual capacitance and its ESR (equivalent series resistance). Old electrolytics that start to dry out and die lose capacitance and their ESR increases. Both of these parameter changes degrade the cap's ability to do its intended job. There are techniques for attempting to reform a capacitor. I don't recommend them. They need replacing.

The old multi-capacitor electrolytic cans intentionally used the can as a common ground. These were common in tube radios of the 1950s, for example. They're also common in electric guitar amplifiers of the era. I've seen many YouTube videos by The Guitologist and Mr Carlson, both restorers of old tube gear, who routinely replace these multi-cap cans with multiple, modern electrolytics. But they always measure first.

You have to measure these two values (capacitance and ESR) to really know about a capacitor's health. In the old days, when you and I worked for HP, you spent lots of money to buy an instrument to measure these values. Today, you either use the capacitance range on your expensive DMM (assuming you have one) or you spend $11.95 on eBay for a general-purpose component tester that can test capacitors, resistors, coils, bipolar transistors, FETs, and diodes:

https://www.ebay.com/itm/12864-Mega328-ESR-Transistor-Resistor-Diode-Capacitor-Mosfet-Tester-w-Test-hook/222084192100?hash=item33b53fd764:g:ZvEAAOSwlGtbV01I

I have one of these testers. They work surprisingly well for the money. A simple on-board microcontroller does all the hard work including driving the tester's LCD (which looks like it was salvaged from an old mobile phone). If you're going to be looking at all of those caps (and other old parts) in your three 9845 PSUs, you might consider getting one.


--Steve



On 9/9/2018 11:26 PM, Lee A. White wrote:
Newbie Question - are the electrolytic capacitors with two leads coming out of the same end of the can supposed to have one lead that is grounded to the can, or are they both supposed to be isolated electrically? I seem to have some with leads that that are both isolated and some that are not. Is one lead shorting to the can a sign they are bad? Worse yet, seems to be intermittent on some of them. I am not ready to start pulling components quite yet so I can't just look to see how they are built. I do know that the caps with one axial lead coming out of each end often do have one lead that is grounded to the can.
 
Lee
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

-- 
Steve Leibson

Phone (Cell): 408-910-5992
Phone (Home): 408-292-4930


Please feel free to link to me on LinkedIn


History site: www.hp9825.com

Re: DEAD 9845 power supplies

Precaud
 

There's lots of info on the DE-5000 out there, especially eevblog.com .

IET Labs imported the DE-5000 and sold it for near $400. A couple years later DER started selling it direct. IET now sells the DE-6000, which is a DE-5000 with cal specs verified to slightly tighter standards.

The DE-5000 is hard to beat.

As with any meter, make sure you discharge the caps before testing them.

John

On 9/21/2018 2:02 PM, Jack Rubin wrote:
Mmm - that looks pretty nice! Have you used both this and the Peak?
Jack

-----Original Message-----
From: VintHPcom@groups.io [mailto:VintHPcom@groups.io] On Behalf Of Precaud
Sent: Friday, September 21, 2018 2:39 PM
To: VintHPcom@groups.io
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Measuring caps in-circuit works generally ok unless the cap is in parallel with other passives of similar impedance in the circuit.

For less than the Peak, you can get a DER DE-5000 with tweezers and clips, and have a very good 100Hz-100kHz LCR meter.

https://www.ebay.com/sch/i.html?_armrs=1&_sofindtype=13%3FssPageName%3Dh%3Ah%3Afitem%3AUS&_from=&_nkw=der+de-5000&_in_kw=1&_ex_kw=&_sacat=12576&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=87501&_sargn=-1%26saslc%3D1&_salic=1&_sop=12&_dmd=1&_ipg=50&_fosrp=1

John

Re: DEAD 9845 power supplies

Jack Rubin
 

Mmm - that looks pretty nice! Have you used both this and the Peak?
Jack

-----Original Message-----
From: VintHPcom@groups.io [mailto:VintHPcom@groups.io] On Behalf Of Precaud
Sent: Friday, September 21, 2018 2:39 PM
To: VintHPcom@groups.io
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Measuring caps in-circuit works generally ok unless the cap is in parallel with other passives of similar impedance in the circuit.

For less than the Peak, you can get a DER DE-5000 with tweezers and clips, and have a very good 100Hz-100kHz LCR meter.

https://www.ebay.com/sch/i.html?_armrs=1&_sofindtype=13%3FssPageName%3Dh%3Ah%3Afitem%3AUS&_from=&_nkw=der+de-5000&_in_kw=1&_ex_kw=&_sacat=12576&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=87501&_sargn=-1%26saslc%3D1&_salic=1&_sop=12&_dmd=1&_ipg=50&_fosrp=1

John

On 9/21/2018 1:04 PM, Jack Rubin wrote:
I like the Peak Atlas line of testers quite a bit. Here’s the ESR
meter
-
www.ebay.com/itm/Peak-Atlas-ESR70-In-Circuit-Capacitor-ESR-Meter-Teste
r-Warranty-Latest-Version/113235969801?_trkparms=aid%3D555017%26algo%3
DPL.CASSINI%26ao%3D1%26asc%3D20150817211623%26meid%3Da0588a63c5e949e0a
a982efe1606acb8%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D113235969
801&_trksid=p2045573.c100505.m3226
<http://www.ebay.com/itm/Peak-Atlas-ESR70-In-Circuit-Capacitor-ESR-Met
er-Tester-Warranty-Latest-Version/113235969801?_trkparms=aid%3D555017%
26algo%3DPL.CASSINI%26ao%3D1%26asc%3D20150817211623%26meid%3Da0588a63c
5e949e0aa982efe1606acb8%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D1
13235969801&_trksid=p2045573.c100505.m3226>
– but there are several others that are also quite helpful.

Jack

*From:*VintHPcom@groups.io [mailto:VintHPcom@groups.io] *On Behalf Of
*Lee A. White
*Sent:* Friday, September 21, 2018 2:44 PM
*To:* VintHPcom@groups.io
*Subject:* Re: [VintHPcom] DEAD 9845 power supplies

Guys

The only instrument I have to measure capacitors is an ancient
whetstone bridge with capacitance settings and an "eye tube" for the
indicator. I am sure the reference capacitors in this instrument are
almost certainly dead or have drifted considerably.

So, what is a good reasonable affordable instrument for measuring
capacitors?

Can you test them in-circuit or do you usually need to pull up one or
both leads?

If you have to pull them to test them - wouldn't it make sense to just
replace them with new ones?

NEXT ISSUE:

I have three PSU and each of the 66582 boars has different voltage
test results when in a complete PSU assembly and powered up. In
particular, the voltages on the two main filter caps - C17 and C 18.
One PSU has 0 VDC on both, one had ) VDC on one, and one hast the
correct voltage on both. I am thinking the best approach is to isolate
this board, power it up, and trace down the faults in this section,
and also test out the start up power supply section. Anyone see any difficulty in doing this?
Any chance of blowing something on the board doing so? I have already
made measurements of the transformers, fuses, and bridges - in circuit
- and can not detect any differences between the three boards.

Lee

*From:*Steve Leibson <mailto:steven.leibson@...>

*Sent:*Monday, September 10, 2018 8:54 AM

*To:*VintHPcom@groups.io <mailto:VintHPcom@groups.io>

*Subject:*Re: [VintHPcom] DEAD 9845 power supplies

Hi Lee,

I don't know about the specifics of the electrolytics used in the 9845
and I can't find a photo online, but there's no general "supposed to"
rule when it comes to capacitor case grounding. Most of today's radial
electrolytics have shrink-wrapped cases to insulate them. The fact
that the grounding is intermittent is certainly troubling.

What you really want to know about a capacitor (any capacitor) is its
actual capacitance and its ESR (equivalent series resistance). Old
electrolytics that start to dry out and die lose capacitance and their
ESR increases. Both of these parameter changes degrade the cap's
ability to do its intended job. There are techniques for attempting to
reform a capacitor. I don't recommend them. They need replacing.

The old multi-capacitor electrolytic cans intentionally used the can
as a common ground. These were common in tube radios of the 1950s, for
example. They're also common in electric guitar amplifiers of the era.
I've seen many YouTube videos by The Guitologist and Mr Carlson, both
restorers of old tube gear, who routinely replace these multi-cap cans
with multiple, modern electrolytics. But they always measure first.

You have to measure these two values (capacitance and ESR) to really
know about a capacitor's health. In the old days, when you and I
worked for HP, you spent lots of money to buy an instrument to measure
these values. Today, you either use the capacitance range on your
expensive DMM (assuming you have one) or you spend $11.95 on eBay for
a general-purpose component tester that can test capacitors,
resistors, coils, bipolar transistors, FETs, and diodes:

https://www.ebay.com/itm/12864-Mega328-ESR-Transistor-Resistor-Diode-C
apacitor-Mosfet-Tester-w-Test-hook/222084192100?hash=item33b53fd764:g:
ZvEAAOSwlGtbV01I

I have one of these testers. They work surprisingly well for the money.
A simple on-board microcontroller does all the hard work including
driving the tester's LCD (which looks like it was salvaged from an old
mobile phone). If you're going to be looking at all of those caps (and
other old parts) in your three 9845 PSUs, you might consider getting one.

--Steve

On 9/9/2018 11:26 PM, Lee A. White wrote:

Newbie Question - are the electrolytic capacitors with two leads
coming out of the same end of the can supposed to have one lead that
is grounded to the can, or are they both supposed to be isolated
electrically? I seem to have some with leads that that are both
isolated and some that are not. Is one lead shorting to the can a
sign they are bad? Worse yet, seems to be intermittent on some of
them. I am not ready to start pulling components quite yet so I
can't just look to see how they are built. I do know that the caps
with one axial lead coming out of each end often do have one lead
that is grounded to the can.

Lee

Your Subscription <https://groups.io/g/VintHPcom/editsub/1154203> |
Contact Group Owner <mailto:VintHPcom+owner@groups.io> | Unsubscribe
<https://groups.io/g/VintHPcom/leave/defanged> [web2464p@...
<mailto:web2464p@...>]



--

Steve Leibson



Phone (Cell): 408-910-5992

Phone (Home): 408-292-4930





Please feel free to link to me on LinkedIn





History site:www.hp9825.com <http://www.hp9825.com>

Re: DEAD 9845 power supplies

Precaud
 

Measuring caps in-circuit works generally ok unless the cap is in
parallel with other passives of similar impedance in the circuit.

For less than the Peak, you can get a DER DE-5000 with tweezers and
clips, and have a very good 100Hz-100kHz LCR meter.

https://www.ebay.com/sch/i.html?_armrs=1&_sofindtype=13%3FssPageName%3Dh%3Ah%3Afitem%3AUS&_from=&_nkw=der+de-5000&_in_kw=1&_ex_kw=&_sacat=12576&_udlo=&_udhi=&_ftrt=901&_ftrv=1&_sabdlo=&_sabdhi=&_samilow=&_samihi=&_sadis=15&_stpos=87501&_sargn=-1%26saslc%3D1&_salic=1&_sop=12&_dmd=1&_ipg=50&_fosrp=1

John

On 9/21/2018 1:04 PM, Jack Rubin wrote:
I like the Peak Atlas line of testers quite a bit. Here’s the ESR meter
-
www.ebay.com/itm/Peak-Atlas-ESR70-In-Circuit-Capacitor-ESR-Meter-Tester-Warranty-Latest-Version/113235969801?_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D20150817211623%26meid%3Da0588a63c5e949e0aa982efe1606acb8%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D113235969801&_trksid=p2045573.c100505.m3226
<http://www.ebay.com/itm/Peak-Atlas-ESR70-In-Circuit-Capacitor-ESR-Meter-Tester-Warranty-Latest-Version/113235969801?_trkparms=aid%3D555017%26algo%3DPL.CASSINI%26ao%3D1%26asc%3D20150817211623%26meid%3Da0588a63c5e949e0aa982efe1606acb8%26pid%3D100505%26rk%3D1%26rkt%3D1%26%26itm%3D113235969801&_trksid=p2045573.c100505.m3226>
– but there are several others that are also quite helpful.

Jack

*From:*VintHPcom@groups.io [mailto:VintHPcom@groups.io] *On Behalf Of
*Lee A. White
*Sent:* Friday, September 21, 2018 2:44 PM
*To:* VintHPcom@groups.io
*Subject:* Re: [VintHPcom] DEAD 9845 power supplies

Guys

The only instrument I have to measure capacitors is an ancient whetstone
bridge with capacitance settings and an "eye tube" for the indicator. I
am sure the reference capacitors in this instrument are almost certainly
dead or have drifted considerably.

So, what is a good reasonable affordable instrument for measuring
capacitors?

Can you test them in-circuit or do you usually need to pull up one or
both leads?

If you have to pull them to test them - wouldn't it make sense to just
replace them with new ones?

NEXT ISSUE:

I have three PSU and each of the 66582 boars has different voltage test
results when in a complete PSU assembly and powered up. In particular,
the voltages on the two main filter caps - C17 and C 18. One PSU has 0
VDC on both, one had ) VDC on one, and one hast the correct voltage on
both. I am thinking the best approach is to isolate this board, power it
up, and trace down the faults in this section, and also test out the
start up power supply section. Anyone see any difficulty in doing this?
Any chance of blowing something on the board doing so? I have already
made measurements of the transformers, fuses, and bridges - in circuit -
and can not detect any differences between the three boards.

Lee

*From:*Steve Leibson <mailto:steven.leibson@...>

*Sent:*Monday, September 10, 2018 8:54 AM

*To:*VintHPcom@groups.io <mailto:VintHPcom@groups.io>

*Subject:*Re: [VintHPcom] DEAD 9845 power supplies

Hi Lee,

I don't know about the specifics of the electrolytics used in the 9845
and I can't find a photo online, but there's no general "supposed to"
rule when it comes to capacitor case grounding. Most of today's radial
electrolytics have shrink-wrapped cases to insulate them. The fact that
the grounding is intermittent is certainly troubling.

What you really want to know about a capacitor (any capacitor) is its
actual capacitance and its ESR (equivalent series resistance). Old
electrolytics that start to dry out and die lose capacitance and their
ESR increases. Both of these parameter changes degrade the cap's ability
to do its intended job. There are techniques for attempting to reform a
capacitor. I don't recommend them. They need replacing.

The old multi-capacitor electrolytic cans intentionally used the can as
a common ground. These were common in tube radios of the 1950s, for
example. They're also common in electric guitar amplifiers of the era.
I've seen many YouTube videos by The Guitologist and Mr Carlson, both
restorers of old tube gear, who routinely replace these multi-cap cans
with multiple, modern electrolytics. But they always measure first.

You have to measure these two values (capacitance and ESR) to really
know about a capacitor's health. In the old days, when you and I worked
for HP, you spent lots of money to buy an instrument to measure these
values. Today, you either use the capacitance range on your expensive
DMM (assuming you have one) or you spend $11.95 on eBay for a
general-purpose component tester that can test capacitors, resistors,
coils, bipolar transistors, FETs, and diodes:

https://www.ebay.com/itm/12864-Mega328-ESR-Transistor-Resistor-Diode-Capacitor-Mosfet-Tester-w-Test-hook/222084192100?hash=item33b53fd764:g:ZvEAAOSwlGtbV01I

I have one of these testers. They work surprisingly well for the money.
A simple on-board microcontroller does all the hard work including
driving the tester's LCD (which looks like it was salvaged from an old
mobile phone). If you're going to be looking at all of those caps (and
other old parts) in your three 9845 PSUs, you might consider getting one.

--Steve

On 9/9/2018 11:26 PM, Lee A. White wrote:

Newbie Question - are the electrolytic capacitors with two leads
coming out of the same end of the can supposed to have one lead that
is grounded to the can, or are they both supposed to be isolated
electrically? I seem to have some with leads that that are both
isolated and some that are not. Is one lead shorting to the can a
sign they are bad? Worse yet, seems to be intermittent on some of
them. I am not ready to start pulling components quite yet so I
can't just look to see how they are built. I do know that the caps
with one axial lead coming out of each end often do have one lead
that is grounded to the can.

Lee

Your Subscription <https://groups.io/g/VintHPcom/editsub/1154203> |
Contact Group Owner <mailto:VintHPcom+owner@groups.io> | Unsubscribe
<https://groups.io/g/VintHPcom/leave/defanged> [web2464p@...
<mailto:web2464p@...>]



--

Steve Leibson



Phone (Cell): 408-910-5992

Phone (Home): 408-292-4930





Please feel free to link to me on LinkedIn





History site:www.hp9825.com <http://www.hp9825.com>

Re: DEAD 9845 power supplies

Jack Rubin
 

From: VintHPcom@groups.io [mailto:VintHPcom@groups.io] On Behalf Of Lee A. White
Sent: Friday, September 21, 2018 2:44 PM
To: VintHPcom@groups.io
Subject: Re: [VintHPcom] DEAD 9845 power supplies

 

Guys

 

The only instrument I have to measure capacitors is an ancient whetstone bridge with capacitance settings and an "eye tube" for the indicator. I am sure the reference capacitors in this instrument are almost certainly dead or have drifted considerably.

 

So, what is a good reasonable affordable instrument for measuring capacitors?

 

Can you test them in-circuit or do you usually need to pull up one or both leads?

 

If you have to pull them to test them - wouldn't it make sense to just replace them with new ones?

 

 

NEXT ISSUE:

 

I have three PSU and each of the 66582 boars has different voltage test results when in a complete PSU assembly and powered up. In particular, the voltages on the two main filter caps - C17 and C 18. One PSU has 0 VDC on both, one had ) VDC on one, and one hast the correct voltage on both. I am thinking the best approach is to isolate this board, power it up, and trace down the faults in this section, and also test out the start up power supply section. Anyone see any difficulty in doing this? Any chance of blowing something on the board doing so? I have already made measurements of the transformers, fuses, and bridges - in circuit - and can not detect any differences between the three boards.

 

 

Lee 

 

Sent: Monday, September 10, 2018 8:54 AM

Subject: Re: [VintHPcom] DEAD 9845 power supplies

 

Hi Lee,

I don't know about the specifics of the electrolytics used in the 9845 and I can't find a photo online, but there's no general "supposed to" rule when it comes to capacitor case grounding. Most of today's radial electrolytics have shrink-wrapped cases to insulate them. The fact that the grounding is intermittent is certainly troubling.

What you really want to know about a capacitor (any capacitor) is its actual capacitance and its ESR (equivalent series resistance). Old electrolytics that start to dry out and die lose capacitance and their ESR increases. Both of these parameter changes degrade the cap's ability to do its intended job. There are techniques for attempting to reform a capacitor. I don't recommend them. They need replacing.

The old multi-capacitor electrolytic cans intentionally used the can as a common ground. These were common in tube radios of the 1950s, for example. They're also common in electric guitar amplifiers of the era. I've seen many YouTube videos by The Guitologist and Mr Carlson, both restorers of old tube gear, who routinely replace these multi-cap cans with multiple, modern electrolytics. But they always measure first.

You have to measure these two values (capacitance and ESR) to really know about a capacitor's health. In the old days, when you and I worked for HP, you spent lots of money to buy an instrument to measure these values. Today, you either use the capacitance range on your expensive DMM (assuming you have one) or you spend $11.95 on eBay for a general-purpose component tester that can test capacitors, resistors, coils, bipolar transistors, FETs, and diodes:

https://www.ebay.com/itm/12864-Mega328-ESR-Transistor-Resistor-Diode-Capacitor-Mosfet-Tester-w-Test-hook/222084192100?hash=item33b53fd764:g:ZvEAAOSwlGtbV01I

I have one of these testers. They work surprisingly well for the money. A simple on-board microcontroller does all the hard work including driving the tester's LCD (which looks like it was salvaged from an old mobile phone). If you're going to be looking at all of those caps (and other old parts) in your three 9845 PSUs, you might consider getting one.

 

--Steve

 

 

On 9/9/2018 11:26 PM, Lee A. White wrote:

Newbie Question - are the electrolytic capacitors with two leads coming out of the same end of the can supposed to have one lead that is grounded to the can, or are they both supposed to be isolated electrically? I seem to have some with leads that that are both isolated and some that are not. Is one lead shorting to the can a sign they are bad? Worse yet, seems to be intermittent on some of them. I am not ready to start pulling components quite yet so I can't just look to see how they are built. I do know that the caps with one axial lead coming out of each end often do have one lead that is grounded to the can.

 

Lee

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



-- 
Steve Leibson
 
Phone (Cell): 408-910-5992
Phone (Home): 408-292-4930
 
 
Please feel free to link to me on LinkedIn
 
 
History site: www.hp9825.com

Re: DEAD 9845 power supplies

Lee A. White
 

Guys
 
The only instrument I have to measure capacitors is an ancient whetstone bridge with capacitance settings and an "eye tube" for the indicator. I am sure the reference capacitors in this instrument are almost certainly dead or have drifted considerably.
 
So, what is a good reasonable affordable instrument for measuring capacitors?
 
Can you test them in-circuit or do you usually need to pull up one or both leads?
 
If you have to pull them to test them - wouldn't it make sense to just replace them with new ones?
 
 
NEXT ISSUE:
 
I have three PSU and each of the 66582 boars has different voltage test results when in a complete PSU assembly and powered up. In particular, the voltages on the two main filter caps - C17 and C 18. One PSU has 0 VDC on both, one had ) VDC on one, and one hast the correct voltage on both. I am thinking the best approach is to isolate this board, power it up, and trace down the faults in this section, and also test out the start up power supply section. Anyone see any difficulty in doing this? Any chance of blowing something on the board doing so? I have already made measurements of the transformers, fuses, and bridges - in circuit - and can not detect any differences between the three boards.
 
 
Lee 

Sent: Monday, September 10, 2018 8:54 AM
Subject: Re: [VintHPcom] DEAD 9845 power supplies

Hi Lee,

I don't know about the specifics of the electrolytics used in the 9845 and I can't find a photo online, but there's no general "supposed to" rule when it comes to capacitor case grounding. Most of today's radial electrolytics have shrink-wrapped cases to insulate them. The fact that the grounding is intermittent is certainly troubling.

What you really want to know about a capacitor (any capacitor) is its actual capacitance and its ESR (equivalent series resistance). Old electrolytics that start to dry out and die lose capacitance and their ESR increases. Both of these parameter changes degrade the cap's ability to do its intended job. There are techniques for attempting to reform a capacitor. I don't recommend them. They need replacing.

The old multi-capacitor electrolytic cans intentionally used the can as a common ground. These were common in tube radios of the 1950s, for example. They're also common in electric guitar amplifiers of the era. I've seen many YouTube videos by The Guitologist and Mr Carlson, both restorers of old tube gear, who routinely replace these multi-cap cans with multiple, modern electrolytics. But they always measure first.

You have to measure these two values (capacitance and ESR) to really know about a capacitor's health. In the old days, when you and I worked for HP, you spent lots of money to buy an instrument to measure these values. Today, you either use the capacitance range on your expensive DMM (assuming you have one) or you spend $11.95 on eBay for a general-purpose component tester that can test capacitors, resistors, coils, bipolar transistors, FETs, and diodes:

https://www.ebay.com/itm/12864-Mega328-ESR-Transistor-Resistor-Diode-Capacitor-Mosfet-Tester-w-Test-hook/222084192100?hash=item33b53fd764:g:ZvEAAOSwlGtbV01I

I have one of these testers. They work surprisingly well for the money. A simple on-board microcontroller does all the hard work including driving the tester's LCD (which looks like it was salvaged from an old mobile phone). If you're going to be looking at all of those caps (and other old parts) in your three 9845 PSUs, you might consider getting one.


--Steve



On 9/9/2018 11:26 PM, Lee A. White wrote:
Newbie Question - are the electrolytic capacitors with two leads coming out of the same end of the can supposed to have one lead that is grounded to the can, or are they both supposed to be isolated electrically? I seem to have some with leads that that are both isolated and some that are not. Is one lead shorting to the can a sign they are bad? Worse yet, seems to be intermittent on some of them. I am not ready to start pulling components quite yet so I can't just look to see how they are built. I do know that the caps with one axial lead coming out of each end often do have one lead that is grounded to the can.
 
Lee
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

-- 
Steve Leibson

Phone (Cell): 408-910-5992
Phone (Home): 408-292-4930


Please feel free to link to me on LinkedIn


History site: www.hp9825.com

New file uploaded to VintHPcom@groups.io

VintHPcom@groups.io Notification <VintHPcom+notification@...>
 

Hello,

This email message is a notification to let you know that a file has been uploaded to the Files area of the VintHPcom@groups.io group.

File: PowerSupply_01.pdf

Uploaded By: Jack Rubin

Description:
First scan attempt of 9845A (Option 100) power suppy - I hope to do better.

You can access this file at the URL:
https://groups.io/g/VintHPcom/files/HP9845/9845A%20Power%20Supply%20Schematic%20-%20provisional/PowerSupply_01.pdf

Cheers,
The Groups.io Team

Re: HP 700/70 Terminal - Keyboard

Martin Hepperle
 

David,

indeed the interesting thing is that this terminal supports the "AlphaWindow" protocol and I just obtained the protocol description via the "cc-talk" message list (cctalk@...).
It should work like a standard text terminal, but in addition the "AlphaWindows" protocol also support text mode windows. It is not an X-Window terminal.
From the little info I have (including your reply), I understand that the C1081C and C1082C keyboards are supported but maybe another 5 Volt one like the C1400A would work too.

Martin

Re: HP 700/70 Terminal - Keyboard

David Collins
 

Martin, the 700/70 was a Unix Windowing terminal and used a C1081C keyboard (PC-AT). 

 

Not much doco in the museum’s database apart from this one…

 

http://www.hpmuseum.net/capcha/freecap_wrap.php?r=4695

 

I suspect the terminal is waiting for a response from a Unix host to start but can’t be 100% sure.  It’s not a standard ascii/text based terminal though.

 

Not much help but hopefully others can provide more info.

 

David Collins..

 

From: VintHPcom@groups.io <VintHPcom@groups.io> On Behalf Of Martin Hepperle
Sent: Monday, 17 September 2018 7:54 PM
To: VintHPcom@groups.io
Subject: [VintHPcom] HP 700/70 Terminal - Keyboard

 

I got a HP 700/70 terminal, albeit without a keyboard.

When I power it up without any keyboard it shows a boot screen like this:

----------------------------------------

             HP 700/70

 HP 700/70 Firmware and Settings Screen
 Copyright 1994 Hewlett-Packard Company
----------------------------------------

No further message is shown, the terminal just stares at me with this boot screen.
It this normal?  I would have expected a keyboard test failure and an error message.

Before I spend time and money on a keyboard just to find out that the terminal has a flaw:

  • Can someone make a test with an HP 700/.. terminal (assuming all HP 700 behave similar)?
  • What happens if you power up a HP 700/.. terminal without a keyboard connected? Does it show an error message?

Using an oscilloscope shows me that the terminal is alive.
On the clock line at the keyboard socket it sends bursts of clock pulses (0->5V) with a total length of approximately 1.76 ms.
These pulses are spaced about 13 us so that during one burst about 1.76ms/13us = 135 pulses are sent.

Speculation:
This could correspond to a polling sequence for 135 keys.
Thus the protocol could be similar to the older HP terminals like the 2392 or the HP 120 and 150 computers.

The keyboard must be designed for 5V operation and for this protocol.
An IBM-AT or PS/2 keyboard does not work.

As far as I understand, the original keyboard for the 700/70 would be either a C1081A (PC-AT style) or a C1082A (ANSI style).
Are there other keyboards which would work?

I could not find HP documentation about the keyboards and the associated terminals.
Searching the web for 700 Terminals gives many keyboard options, but not all have the proper connectors and maybe not the same protocol.

  • 700/20: C1403
  • 700/32: C1421
  • 700/44: C1408
  • 700/66: C1408
  • 700/70: C1408?, C1082 (AT), C1083 (ANSI)
  • 700/92: C1400, C3340?
  • 700/94: C1400
  • 700/96: C1400, C3340?

Do I need exactly a C1082 or C1083 or would any of the C1400, C1408 also fit?
Confused,
Martin

HP 700/70 Terminal - Keyboard

Martin Hepperle
 

I got a HP 700/70 terminal, albeit without a keyboard.

When I power it up without any keyboard it shows a boot screen like this:

----------------------------------------

             HP 700/70

 HP 700/70 Firmware and Settings Screen
 Copyright 1994 Hewlett-Packard Company
----------------------------------------

No further message is shown, the terminal just stares at me with this boot screen.
It this normal?  I would have expected a keyboard test failure and an error message.

Before I spend time and money on a keyboard just to find out that the terminal has a flaw:
  • Can someone make a test with an HP 700/.. terminal (assuming all HP 700 behave similar)?
  • What happens if you power up a HP 700/.. terminal without a keyboard connected? Does it show an error message?

Using an oscilloscope shows me that the terminal is alive.
On the clock line at the keyboard socket it sends bursts of clock pulses (0->5V) with a total length of approximately 1.76 ms.
These pulses are spaced about 13 us so that during one burst about 1.76ms/13us = 135 pulses are sent.

Speculation:
This could correspond to a polling sequence for 135 keys.
Thus the protocol could be similar to the older HP terminals like the 2392 or the HP 120 and 150 computers.

The keyboard must be designed for 5V operation and for this protocol.
An IBM-AT or PS/2 keyboard does not work.

As far as I understand, the original keyboard for the 700/70 would be either a C1081A (PC-AT style) or a C1082A (ANSI style).
Are there other keyboards which would work?

I could not find HP documentation about the keyboards and the associated terminals.
Searching the web for 700 Terminals gives many keyboard options, but not all have the proper connectors and maybe not the same protocol.

  • 700/20: C1403
  • 700/32: C1421
  • 700/44: C1408
  • 700/66: C1408
  • 700/70: C1408?, C1082 (AT), C1083 (ANSI)
  • 700/92: C1400, C3340?
  • 700/94: C1400
  • 700/96: C1400, C3340?
Do I need exactly a C1082 or C1083 or would any of the C1400, C1408 also fit?
Confused,
Martin

Swap stepper motor parts from a OA-D32W-11 into a -10 unit?

Tony Goodhew
 

Hi All,

I have one of the drives in my 9122D working now but the other drive fails to initialize a disk. Using the self tests, it passes Drive seek, Motor speed but fails Write/verify or Format disc.

Listening to the drive it sounds like there is a bit of grinding from the steeper motor for the head - Not sure that is the issue but I'm wondering if I can replace those parts from one of the dead drives I have (where the heads have been ripped off) - Both of the dead drives are OA-D32W-11 units.

Before I go pulling these drives apart I thought I'd ask if anyone has done this before and is it even possible?

Thanks,

TonyG

Re: HP 16505A Operating System Upgrade

Dan P
 

Thanks for the pointer but I already have the clean install and disk image for 1.40 that I received from Glen.
The 16505A using the image from Glen works great but is based on HP-UX 9.05 which is ancient and is also pretty crippled as a lot of the functionality is not installed.

So I was hoping to upgrade the actual OS to something newer and then just transfer the analyzer program to the new OS and have a more modern (if still obsolete) OS and still be able to use the analyzer.

That is where the issues came in, in that the analyzer program uses the SCSI passthough driver which does not seem to work correctly on anything other than version 9.05 of HP-UX.

Re: Viper version of the SS/80 Exerciser software

Tony Goodhew
 

Actually it looks like this was originally on a HP85 tape and the SERVC module which would be most useful doesn’t seem to be included on any oif the tape to image conversions.

 

Thanks again everyone for the help – Really appreciate it.

 

TonyG

 

Sent from Mail for Windows 10

 


From: VintHPcom@groups.io <VintHPcom@groups.io> on behalf of Tony Goodhew <tony_goodhew@...>
Sent: Tuesday, September 11, 2018 7:12:59 AM
To: VintHPcom@groups.io
Subject: Re: [VintHPcom] Viper version of the SS/80 Exerciser software
 

Thanks Sven – Appreciate it – Looks like I’ll need to try and find the original SS/80 program mentioned by the service manual:

 

(pg 4-6) If an HP-85 and the SS/80 Exerciser, P/N 5010-0310, are available it is recommended that the Exerciser be used to diagnose the failure and verify a repair.

 

Really appreciate you going to the effort to test.

 

Thanks,

 

TonyG

 

Sent from Mail for Windows 10

 


From: VintHPcom@groups.io <VintHPcom@groups.io> on behalf of Sven Schnelle <svens@...>
Sent: Monday, September 10, 2018 11:51:20 PM
To: VintHPcom@groups.io
Subject: Re: [VintHPcom] Viper version of the SS/80 Exerciser software
 
Hi Tony,


i did a quick test in a virtual /360 with a 9122D floppy drive (also
virtual), and the CS80 Exerciser states that it doesn't support SS/80:


https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fstackframe.org%2Fcs80.png&amp;data=02%7C01%7C%7Ca7cf4fa3e53f46e0c56508d617b2fe1d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636722454860389548&amp;sdata=OCaxFzxVMcmILk55mNXpbHBeBlCJ2k0qovMDRmN1e%2FQ%3D&amp;reserved=0


So you definitely don't have to worry about getting this thing to run on
your Viper card.


Regards

Sven


On 09/10/2018 10:01 PM, Tony Goodhew wrote:
> Hi All,
>
> I've started work on cleaning up the drives in the 9122D unit and
> they're moving freely but still failing to initialize. While I was
> reading the service manual I noted a mention of an automated service
> program called the "SS/80 Exerciser".
>
> I've looked around for this and found a link to a Teledisk version of
> something I assume is similar - The CS/80 Exerciser
> (https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.hpmuseum.net%2Fdisplay_item.php%3Fsw%3D249&amp;data=02%7C01%7C%7Ca7cf4fa3e53f46e0c56508d617b2fe1d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636722454860389548&amp;sdata=OgJga6nlHIuKAC6C5lp7KcxnLh3sANbAIpQIMOSr%2BTk%3D&amp;reserved=0) and then links
> saying this TD0 is corrupt and that a fixed version exists over at
> GitHub (https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fmagore%2Fhp85disk%2Ftree%2Fmaster%2Flif&amp;data=02%7C01%7C%7Ca7cf4fa3e53f46e0c56508d617b2fe1d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636722454860389548&amp;sdata=6RzdUkhMlGhTzI4cLB5xv0%2Fsekc0k0JJNsCInJO8ldY%3D&amp;reserved=0).
>
> However I have had no success in getting any of these to work using
> the HP 82324A Viper card. I either get errors when writing to the PC
> drive (where I can format the LIF disk but the TD0 seems to have
> sector errors towards the end) or I can get a LIF disk but the file
> format is unrecognized by the Viper card (GET, LOAD, etc all return
> incorrect file format).
>
> Anyone happen to have a working version of this or any tips for what I
> might not be doing to get the software to run?
>
> Thanks,
>
> TonyG
>




Re: Viper version of the SS/80 Exerciser software

Tony Goodhew
 

Thanks Sven – Appreciate it – Looks like I’ll need to try and find the original SS/80 program mentioned by the service manual:

 

(pg 4-6) If an HP-85 and the SS/80 Exerciser, P/N 5010-0310, are available it is recommended that the Exerciser be used to diagnose the failure and verify a repair.

 

Really appreciate you going to the effort to test.

 

Thanks,

 

TonyG

 

Sent from Mail for Windows 10

 


From: VintHPcom@groups.io <VintHPcom@groups.io> on behalf of Sven Schnelle <svens@...>
Sent: Monday, September 10, 2018 11:51:20 PM
To: VintHPcom@groups.io
Subject: Re: [VintHPcom] Viper version of the SS/80 Exerciser software
 
Hi Tony,


i did a quick test in a virtual /360 with a 9122D floppy drive (also
virtual), and the CS80 Exerciser states that it doesn't support SS/80:


https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fstackframe.org%2Fcs80.png&amp;data=02%7C01%7C%7Ca7cf4fa3e53f46e0c56508d617b2fe1d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636722454860389548&amp;sdata=OCaxFzxVMcmILk55mNXpbHBeBlCJ2k0qovMDRmN1e%2FQ%3D&amp;reserved=0


So you definitely don't have to worry about getting this thing to run on
your Viper card.


Regards

Sven


On 09/10/2018 10:01 PM, Tony Goodhew wrote:
> Hi All,
>
> I've started work on cleaning up the drives in the 9122D unit and
> they're moving freely but still failing to initialize. While I was
> reading the service manual I noted a mention of an automated service
> program called the "SS/80 Exerciser".
>
> I've looked around for this and found a link to a Teledisk version of
> something I assume is similar - The CS/80 Exerciser
> (https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.hpmuseum.net%2Fdisplay_item.php%3Fsw%3D249&amp;data=02%7C01%7C%7Ca7cf4fa3e53f46e0c56508d617b2fe1d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636722454860389548&amp;sdata=OgJga6nlHIuKAC6C5lp7KcxnLh3sANbAIpQIMOSr%2BTk%3D&amp;reserved=0) and then links
> saying this TD0 is corrupt and that a fixed version exists over at
> GitHub (https://nam01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com%2Fmagore%2Fhp85disk%2Ftree%2Fmaster%2Flif&amp;data=02%7C01%7C%7Ca7cf4fa3e53f46e0c56508d617b2fe1d%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C636722454860389548&amp;sdata=6RzdUkhMlGhTzI4cLB5xv0%2Fsekc0k0JJNsCInJO8ldY%3D&amp;reserved=0).
>
> However I have had no success in getting any of these to work using
> the HP 82324A Viper card. I either get errors when writing to the PC
> drive (where I can format the LIF disk but the TD0 seems to have
> sector errors towards the end) or I can get a LIF disk but the file
> format is unrecognized by the Viper card (GET, LOAD, etc all return
> incorrect file format).
>
> Anyone happen to have a working version of this or any tips for what I
> might not be doing to get the software to run?
>
> Thanks,
>
> TonyG
>




Re: Viper version of the SS/80 Exerciser software

Sven Schnelle <svens@...>
 

Hi Tony,


i did a quick test in a virtual /360 with a 9122D floppy drive (also
virtual), and the CS80 Exerciser states that it doesn't support SS/80:


http://stackframe.org/cs80.png


So you definitely don't have to worry about getting this thing to run on
your Viper card.


Regards

Sven

On 09/10/2018 10:01 PM, Tony Goodhew wrote:
Hi All,

I've started work on cleaning up the drives in the 9122D unit and
they're moving freely but still failing to initialize. While I was
reading the service manual I noted a mention of an automated service
program called the "SS/80 Exerciser".

I've looked around for this and found a link to a Teledisk version of
something I assume is similar - The CS/80 Exerciser
(http://www.hpmuseum.net/display_item.php?sw=249) and then links
saying this TD0 is corrupt and that a fixed version exists over at
GitHub (https://github.com/magore/hp85disk/tree/master/lif).

However I have had no success in getting any of these to work using
the HP 82324A Viper card. I either get errors when writing to the PC
drive (where I can format the LIF disk but the TD0 seems to have
sector errors towards the end) or I can get a LIF disk but the file
format is unrecognized by the Viper card (GET, LOAD, etc all return
incorrect file format).

Anyone happen to have a working version of this or any tips for what I
might not be doing to get the software to run?

Thanks,

TonyG

Re: Viper version of the SS/80 Exerciser software

Sven Schnelle <svens@...>
 

Hi Tony,

i have various /300 systems and a 9122D floppy drive. If you want, i can
fetch the LIF files from the disk and test whether the CS/80 disk
exerciser works at all with the 9122D floppy drive.


Regards

Sven

On 09/10/2018 10:01 PM, Tony Goodhew wrote:
Hi All,

I've started work on cleaning up the drives in the 9122D unit and
they're moving freely but still failing to initialize. While I was
reading the service manual I noted a mention of an automated service
program called the "SS/80 Exerciser".

I've looked around for this and found a link to a Teledisk version of
something I assume is similar - The CS/80 Exerciser
(http://www.hpmuseum.net/display_item.php?sw=249) and then links
saying this TD0 is corrupt and that a fixed version exists over at
GitHub (https://github.com/magore/hp85disk/tree/master/lif).

However I have had no success in getting any of these to work using
the HP 82324A Viper card. I either get errors when writing to the PC
drive (where I can format the LIF disk but the TD0 seems to have
sector errors towards the end) or I can get a LIF disk but the file
format is unrecognized by the Viper card (GET, LOAD, etc all return
incorrect file format).

Anyone happen to have a working version of this or any tips for what I
might not be doing to get the software to run?

Thanks,

TonyG

Re: Viper version of the SS/80 Exerciser software

Sven Schnelle <svens@...>
 

Hi Rik,


are you sure about that? I used various Pascal compiled programs on my
'030 systems - including the 300 Series Test Software, Pascal itself,
and also the CS/80 Exerciser (ok, i only booted it because i have no
CS/80 drives). What's definitely the case is that these programs don't
run on the '040 which was used in the /380 and /382, because that
processor used different exception stack frames that this software can't
handle. At least not the versions i have. Pascal was available for the
/38x though.

Regards
Sven

On 09/10/2018 11:28 PM, Rik Bos wrote:

Tony,

 

That version only runs on a 9816 / 68K processor, not on a 68030
processor.

The software is built around the P-system OS, it’s a compiled Pascal
program.

 

-Rik

 

*Van:* VintHPcom@groups.io <VintHPcom@groups.io> *Namens *Tony Goodhew
*Verzonden:* maandag 10 september 2018 22:02
*Aan:* VintHPcom@groups.io
*Onderwerp:* [VintHPcom] Viper version of the SS/80 Exerciser software

 

Hi All,

I've started work on cleaning up the drives in the 9122D unit and
they're moving freely but still failing to initialize. While I was
reading the service manual I noted a mention of an automated service
program called the "SS/80 Exerciser".

I've looked around for this and found a link to a Teledisk version of
something I assume is similar - The CS/80 Exerciser
(http://www.hpmuseum.net/display_item.php?sw=249) and then links
saying this TD0 is corrupt and that a fixed version exists over at
GitHub (https://github.com/magore/hp85disk/tree/master/lif).

However I have had no success in getting any of these to work using
the HP 82324A Viper card. I either get errors when writing to the PC
drive (where I can format the LIF disk but the TD0 seems to have
sector errors towards the end) or I can get a LIF disk but the file
format is unrecognized by the Viper card (GET, LOAD, etc all return
incorrect file format).

Anyone happen to have a working version of this or any tips for what I
might not be doing to get the software to run?

Thanks,

TonyG

Re: Viper version of the SS/80 Exerciser software

 

Tony,

I don't know if there are other versions, but I've never seen them.

-Rik




On Mon, Sep 10, 2018 at 11:31 PM +0200, "Tony Goodhew" <tony_goodhew@...> wrote:

Thanks Rik, I’ll stop poking at it then.

 

Do you happen to know if there ever was a version of the SS/80 Exerciser that would work with the Viper? Or should I just content myself with the inbuilt self test options for the 9122D?

 

Thanks

 

TonyG

 

Sent from Mail for Windows 10

 


From: VintHPcom@groups.io <VintHPcom@groups.io> on behalf of Rik Bos <hp-fix@...>
Sent: Monday, September 10, 2018 2:28:34 PM
To: VintHPcom@groups.io
Subject: Re: [VintHPcom] Viper version of the SS/80 Exerciser software
 

Tony,

 

That version only runs on a 9816 / 68K processor, not on a 68030 processor.

The software is built around the P-system OS, it’s a compiled Pascal program.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Tony Goodhew
Verzonden: maandag 10 september 2018 22:02
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] Viper version of the SS/80 Exerciser software

 

Hi All,

I've started work on cleaning up the drives in the 9122D unit and they're moving freely but still failing to initialize. While I was reading the service manual I noted a mention of an automated service program called the "SS/80 Exerciser".

I've looked around for this and found a link to a Teledisk version of something I assume is similar - The CS/80 Exerciser (http://www.hpmuseum.net/display_item.php?sw=249) and then links saying this TD0 is corrupt and that a fixed version exists over at GitHub (https://github.com/magore/hp85disk/tree/master/lif).

However I have had no success in getting any of these to work using the HP 82324A Viper card. I either get errors when writing to the PC drive (where I can format the LIF disk but the TD0 seems to have sector errors towards the end) or I can get a LIF disk but the file format is unrecognized by the Viper card (GET, LOAD, etc all return incorrect file format).

Anyone happen to have a working version of this or any tips for what I might not be doing to get the software to run?

Thanks,

TonyG