Date   

TM module pull tab needed

Paul Amaranth
 

I recently picked up an SG503 from a Tek ebay chipxs auction.

I was a bit annoyed since the item sent did not match the
item pictured. It was a lot dirtier and, more importantly,
it was missing the pull tab. Well, it was shipped in a
Tektronix box, that has to count for something. I'm
still waiting for a response from them.

Does anyone have a spare pull tab from a dead TM module?

Alternatively, does anyone have a dead TM module they want
to sell cheap? (but it does need the pull tab)

thanks

--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@AuroraGrp.Com | Unix & Windows


Re: C5C Scope Camera: It appears the camera is never turned off, draining the battery

Brad Thompson <brad.thompson@...>
 

On 2/10/2013 8:45 PM, Peter Bunge wrote:
Is there any chance of getting a schematic of the flash circuit?
I have an old C5B and plan to use it with a modern digital camera on my
Tek 2467B 'scope and my HP 8505A Network analyzer.
The flash lights up the phosphor to backlight the grid on the 8505A
which does not have scale illumination. My email should show up to members.
Peter.
Hello, Peter--

As an alternative, you might want to investigate using
ultraviolet-emitting LEDs, which you could arrange in a frame that fits around the CRT's outer edges and illuminates the CRT's face.

You could bypass the original flash circuitry and devise a one-shot
multivibrator (e.g., a 555 timer) to pulse the LEDs.

73--

Brad AA1IP


Re: C5C Scope Camera: It appears the camera is never turned off, draining the battery

rovmkr
 

Is there any chance of getting a schematic of the flash circuit?
I have an old C5B and plan to use it with a modern digital camera on my Tek 2467B 'scope and my HP 8505A Network analyzer.
The flash lights up the phosphor to backlight the grid on the 8505A which does not have scale illumination. My email should show up to members.
Peter.

--- In TekScopes@yahoogroups.com, "Dennis Tillman" wrote:

FOLLOWUP:

I switched to my DM5010 which can display down to units of nAmps! And it
appears the current eventually stabilizes around 2 or 3 nAmps which I would
assume is about the limit of the instrument. Pretty impressive instrument -
Tek bought the guts from Fluke, another (now) Danaher company. Presumably
the current goes to zero after the caps are fully charged which took about
30 minutes.



I still don't see how power to the electronics gets disconnected from the
battery. The only mention in the Theory of Operation about the batteries is
the paragraph that says "When new batteries are installed, the shutter may
cycle. The Low Frequency Oscillator also ensures that the shutter will be in
a closed position after new batteries are installed." Pg 3-2.



Dennis



From: TekScopes@yahoogroups.com [mailto:TekScopes@yahoogroups.com] On Behalf
Of Dennis Tillman
Sent: Tuesday, June 05, 2012 9:53 PM



I am looking at the schematic for the C5C scope camera (Diagram #1 SHUTTER
CONTROL) in the manual and as near as I can tell the 6V battery pack is
never disconnected from the camera electronics which would drain the battery
eventually. The only switch on the unit is the shutter timer switch which
has two positions: TIMED SHUTTER and SPRING RETURN. In the neutral center
position the switch leaves part of a gate ungrounded, but power is still
flowing all the time from the battery across two 100uF caps (for energy
storage) to most of the rest of the circuit.



My DM501A confirms there is about 50uA or less (it's getting down to the
residual capability of the DM501A) flowing all the time once the
electrolytics are fully charged again after the shutter solenoid has been
pulsed which discharges them.



Dennis



PS I didn't see a PDF anywhere on the internet or in all the usual document
archives when I looked for one. Fortunately I happen to have an original
manual.


Re: WTB or WTS Tektronix 465

chrismh_somenumber <hogancm@...>
 

Bob,

Thank you for checking on that. Someone else offered me an unknown condition multiplier for cheap, so I accepted.

If that doesn't pan out, I may take you up on your offer, if it's not too late!

Thanks,
Chris

--- In TekScopes@yahoogroups.com, Bob Albert wrote:

Chris,

I checked the manual and the 465B uses the same multiplier.  So I could disassemble my parts unit and remove the multiplier.  I have no idea whether it is good, and it will probably be a bit of work to remove it.

Let me know what you think.

Bob

--- On Sun, 2/10/13, chrismh_somenumber wrote:

From: chrismh_somenumber
Subject: [TekScopes] WTB or WTS Tektronix 465
To: TekScopes@yahoogroups.com
Date: Sunday, February 10, 2013, 3:17 PM
















 









I have a 465 that, except for a blown HV multiplier (part 152-0552-00), works fine. The problem started while I was using it, so I know it works fine.



There is no display on the CRT and I've traced the problem to the -2450 supply. Following the troubleshooting procedures, I disconnected the anode lead and the dummy resistor in the HV supply and the -2450 came up. The manual's suggestion at that point is to replace the HV multiplier.



I was planning on selling this scope anyway so I'm hoping that someone on this list:



1. Wants a 465 that only needs a HV multiplier



2. Has the part I need and wants to sell it (part 152-0552-00)



Thanks,

Chris


Re: Sources for shipping cartons for vintage Tek scopes?

Cliff White
 

I had an even worse problem with peanuts. They got smashed into little pieces, then they floated around inside the scope, ending up under one of the HV covers. I then found out the hard way that peanuts become conductive above a few kilovolts... BANG!!! Ouch...

On 02/10/2013 03:03 PM, David DiGiacomo wrote:
Peanuts should never be used as fill, whether in bags or not.  A heavy
item like a scope crushes them into tiny pellets, and then they no
longer function.  Also, they usually escape from a bag and make a
mess.

With the current dimensional weight formula and shipping rates, it's
very expensive to use oversize boxes.  It's also difficult to make a
box smaller without making it weaker.  (I know some people on this
list are good at it, but most people who try, completely fail.)  I
have found that it almost always pays to buy a right size box over
using a free oversize box.


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Re: Sources for shipping cartons for vintage Tek scopes?

Robert Simpson
 

Bag the peanuts in leftover grocery store bags. That will help them stay in place.
Also, I have used spray foam. Leave the plastic bag open at top over night to dry.
Bob

--- In TekScopes@yahoogroups.com, Gala Dragos wrote:

  deal with the off gas issueput some straws next to the equipment, so they can vent the inside gas.
PU foam will heal itself after some time, it just takes longer for the inside.
Personally I prefer multiple wrappings of bubble wrap, and many many nuts, so many that they cannot move.

--- On Sun, 2/10/13, Dave Daniel wrote:

From: Dave Daniel
Subject: Re: [TekScopes] Sources for shipping cartons for vintage Tek scopes?
To: TekScopes@yahoogroups.com
Date: Sunday, February 10, 2013, 1:58 AM
















 














On 2/9/2013 4:23 PM, Rob wrote:



 



r.e. >>>“I've thought about
using expanding foam from a spray can (the Home Depot
variety) and plastic sheeting to mimic what professional
shippers use, but I've never tried it.�<<<
 
I attempted same. However I ran into
issues because there is no place for the off gas to go
and everything maintains liquid in the bag. It made a
mess as well. If the stuff gets out of the bag and on
equipment it is not forgiving at all.





Did you spray in into a bag? I was thinking I would enclose the
instrument in a sturdy sealed bag, then just spray the foam into the
empty box and hold the instrument off the bottom of the box until
the foam expanded around the instrument.



Dave







 
That said, I think if someone had
more patients and tenacity then I; a scheme to deal with
the off gas issue, allowing the material to solidify.
Thus allowing the idea to be successful.
 
Finally, I have found the boxes at
this link to be  ideal for 7xx3 7000 series scopes.
However, for 7xx4 while serviceable they are a little
tight and I am likely to move to a 26x16x14(or more)
solution.
 
http://www.uline.com/Product/Detail/S-16503/Literature-Mailers/26-x-16-x-12-Jumbo-Carrying-Case

 
Unfortunately, I have also found that
no matter how carefully I pack and/or mark shipments it
seems the post office (and others) have employees who
take it upon themselves to prove how wholly inadequate
my packaging and/or force me to file shipping insurance
claims.  All in all the shipping and lack of care the
main reason that once I have finished my current
supplies of mainframes I will not attempt similar. I
have enjoyed the journey to date but find the “releasing
to the wild� part cumbersome, expensive and totally
unfulfilling.
  
Hopefully helpful
Rob
 


From:
TekScopes@yahoogroups.com
[mailto:TekScopes@yahoogroups.com] On Behalf
Of Dave Daniel

Sent: Saturday, February 09, 2013 4:51 PM

To: TekScopes@yahoogroups.com

Subject: Re: [TekScopes] Sources for
shipping cartons for vintage Tek scopes?


 
 



Not sure about the box, but I use the styrofoam
containers that are used to ship refrigerated
medication; the ones I have available to me are
about 12" each dimension. They are sort of like a
thick-walled styrofoam cooler (about 2-1/2"
thick). I cut each piece (top and bottom) into
quarters and use the quarters as corner blocks for
heavier test equipment.  Perhaps you could get
some of these from a local medical place such as a
hospital or clinic?



I've thought about using expanding foam from a
spray can (the Home Depot variety) and plastic
sheeting to mimic what professional shippers use,
but I've never tried it. I have received many
large items packed that way (I mean by
professionals), and never had a problem with the
gear so shipped.



Cheers,

Dave





On 2/9/2013 3:29 PM,
keithostertag wrote:


 

What are sources for shipping cartons for
vintage Tek scopes, like the 500 and 7000
series? I rarely find boxes that large, or
sturdy. Are there common items/businesses that
use that size/type box?



Any other tips for shipping/packing?



Thanks,

Keith Ostertag


 


Re: 2465 with broken intensity on ebay

ledlensor <rfwebb@...>
 

OK, thanks. So there is a possibility.

Is there any simple test I could give to the seller which might differentiate between the two?

Thanks

--- In TekScopes@yahoogroups.com, David wrote:

The hybrids are known to fail but it could also be caused by a bad DC
restorer which would be easy and cheap to fix.

On Mon, 11 Feb 2013 00:04:53 +0000, Richard Webb
wrote:

Hi,

Just looking at a 2465 on ebay which has just come up. It seems like the
intensity is stuck on full brightness.

I'm just wondering whether this is likely to be an easy fix? I did some
googling and found someone suggesting that a similar problem might be
caused by a faulty hybrid.

Thanks


Re: 2465 with broken intensity on ebay

 

The hybrids are known to fail but it could also be caused by a bad DC
restorer which would be easy and cheap to fix.

On Mon, 11 Feb 2013 00:04:53 +0000, Richard Webb <rfwebb@gmail.com>
wrote:

Hi,

Just looking at a 2465 on ebay which has just come up. It seems like the
intensity is stuck on full brightness.

I'm just wondering whether this is likely to be an easy fix? I did some
googling and found someone suggesting that a similar problem might be
caused by a faulty hybrid.

Thanks


2465 with broken intensity on ebay

Richard Webb <rfwebb@...>
 

Hi,

Just looking at a 2465 on ebay which has just come up. It seems like the intensity is stuck on full brightness.

I'm just wondering whether this is likely to be an easy fix? I did some googling and found someone suggesting that a similar problem might be caused by a faulty hybrid.

Thanks


Re: WTB or WTS Tektronix 465

Bob Albert
 

Chris,

I checked the manual and the 465B uses the same multiplier.  So I could disassemble my parts unit and remove the multiplier.  I have no idea whether it is good, and it will probably be a bit of work to remove it.

Let me know what you think.

Bob


--- On Sun, 2/10/13, chrismh_somenumber wrote:

From: chrismh_somenumber
Subject: [TekScopes] WTB or WTS Tektronix 465
To: TekScopes@...
Date: Sunday, February 10, 2013, 3:17 PM

 

I have a 465 that, except for a blown HV multiplier (part 152-0552-00), works fine. The problem started while I was using it, so I know it works fine.

There is no display on the CRT and I've traced the problem to the -2450 supply. Following the troubleshooting procedures, I disconnected the anode lead and the dummy resistor in the HV supply and the -2450 came up. The manual's suggestion at that point is to replace the HV multiplier.

I was planning on selling this scope anyway so I'm hoping that someone on this list:

1. Wants a 465 that only needs a HV multiplier

2. Has the part I need and wants to sell it (part 152-0552-00)

Thanks,
Chris


Tek 555 + PS on Detroit Craigslist

Paul Amaranth
 

http://detroit.craigslist.org/mcb/atq/3603048849.html

I contacted the seller and he has the power supply and interconnect cable
to go with it. He says the power cord is bad.

I know SOMBODY needs this one.

Paul
--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@AuroraGrp.Com | Unix & Windows


Re: WTB or WTS Tektronix 465

Artekmedia <manuals@...>
 

Someone on the list has done some rebuilding of HV multipliers ...maybe it was for the 2213..the concept is pretty straight forward  electrically. basically caps and diodes. THe challenge is laying out and building (potting) one that doesn't arc when your done

Dave ArtekManuals.com

On 2/10/2013 5:34 PM, Bob Albert wrote:
 

Chris, I don't know the construction of the multiplier but perhaps it can be repaired.

I have a working 465 but it's got a few minor issues.  A parts unit might be nice if it's cheap enough.  I have a 465B parts unit; I wonder if it has the multiplier you need.

I am in Los Angeles.

Bob

--- On Sun, 2/10/13, chrismh_somenumber wrote:

From: chrismh_somenumber
Subject: [TekScopes] WTB or WTS Tektronix 465
To: TekScopes@...
Date: Sunday, February 10, 2013, 3:17 PM

 

I have a 465 that, except for a blown HV multiplier (part 152-0552-00), works fine. The problem started while I was using it, so I know it works fine.

There is no display on the CRT and I've traced the problem to the -2450 supply. Following the troubleshooting procedures, I disconnected the anode lead and the dummy resistor in the HV supply and the -2450 came up. The manual's suggestion at that point is to replace the HV multiplier.

I was planning on selling this scope anyway so I'm hoping that someone on this list:

1. Wants a 465 that only needs a HV multiplier

2. Has the part I need and wants to sell it (part 152-0552-00)

Thanks,
Chris


-- 
Dave Henderson
Manuals@...
www.Artekmanuals.com
PO Box 175
Welch,MN 55089
651-269-4265


Re: WTB or WTS Tektronix 465

Bob Albert
 

Chris, I don't know the construction of the multiplier but perhaps it can be repaired.

I have a working 465 but it's got a few minor issues.  A parts unit might be nice if it's cheap enough.  I have a 465B parts unit; I wonder if it has the multiplier you need.

I am in Los Angeles.

Bob


--- On Sun, 2/10/13, chrismh_somenumber wrote:

From: chrismh_somenumber
Subject: [TekScopes] WTB or WTS Tektronix 465
To: TekScopes@...
Date: Sunday, February 10, 2013, 3:17 PM

 

I have a 465 that, except for a blown HV multiplier (part 152-0552-00), works fine. The problem started while I was using it, so I know it works fine.

There is no display on the CRT and I've traced the problem to the -2450 supply. Following the troubleshooting procedures, I disconnected the anode lead and the dummy resistor in the HV supply and the -2450 came up. The manual's suggestion at that point is to replace the HV multiplier.

I was planning on selling this scope anyway so I'm hoping that someone on this list:

1. Wants a 465 that only needs a HV multiplier

2. Has the part I need and wants to sell it (part 152-0552-00)

Thanks,
Chris


WTB or WTS Tektronix 465

chrismh_somenumber <hogancm@...>
 

I have a 465 that, except for a blown HV multiplier (part 152-0552-00), works fine. The problem started while I was using it, so I know it works fine.

There is no display on the CRT and I've traced the problem to the -2450 supply. Following the troubleshooting procedures, I disconnected the anode lead and the dummy resistor in the HV supply and the -2450 came up. The manual's suggestion at that point is to replace the HV multiplier.

I was planning on selling this scope anyway so I'm hoping that someone on this list:

1. Wants a 465 that only needs a HV multiplier

2. Has the part I need and wants to sell it (part 152-0552-00)

Thanks,
Chris


Re: Repairability of Rohde & Schwarz instruments?

Herbert
 

Hi Brad,

if you or somebody else needs manuals for R&S try

http://www.rainer-foertig.de/unterlagen/RS.htm

the page is in German, but..... you will find out what you need !

Herbert





Am 10.02.2013 20:10, schrieb Brad Thompson:

 

Hello--

On a couple of occasions, I've been tempted to bid on
Rohde & Schwarz instruments but hesitated to do
so because I have no experience in repairing their equipment.

I'm interested in any general comments regarding
availability of technical manuals and spare parts for
R&S equipment relative to Tektronix and Agilent
(Hewlett-Packard) instruments.

To some degree, we've been spoiled, er, we have
benefited by the relatively open technical culture
presented by Tektronix's and Hewlett-Packard's older
products. The rise of custom ICs and modular products
(e.g., power supplies), coupled with concern over
industrial espionage, has affected repairability of
their newer instruments, though.

Feel free to reply to me off-list if you wish and I'll
treat your comments as confidential.

Thanks, and 73--

Brad AA1IP



Re: Repairability of Rohde & Schwarz instruments?

fiftythreebuick <ae5i@...>
 

That really is bad. I would have hoped to see more of a desire to help the user get his gear working than that.....

Very disappointing.

--- In TekScopes@yahoogroups.com, cleyson@... wrote:
<text removed>

No circuit diagrams available and I even asked Rohde & Schwarz
but they said send it to your nearest R&S dealer.
<text removed>

Chris


Re: Repairability of Rohde & Schwarz instruments?

victor.silva
 

My comments are base on my ownership of three R&S units. I have an SMIQ03B, SME03 and SMHU. I find their mechanical construction to be superior to Tek (of the same era) and equal if not superior to HP.

The units I have have superior specs to equivalent HP RF generators. I also find that R&S tend to use more commercially available parts than opt for custom parts, like HP or Tek would.

It's true their Service manuals are hard to get and the one I have been able to get are as good as HPs. Even RF generators from the late 90's or early 2000's still have complete component level service manuals (if you can get them).

The service manuals I have been able to get my hands on has been done by hook or by crook. Not something Dave at Artek Manuals would be willing to do since his purpose in obtaining them is to resell them, mine is simply to keep and use them.

Sources for their service manuals can be ebay (rare) or places that rent originals out.

The rarity of the service manuals can be advantage for the resourceful scrounger, since it keeps prices down on really good test equipment that probably would fetch a lot more if service manuals were easily available.

--Victor

--- In TekScopes@yahoogroups.com, Brad Thompson wrote:

Hello--

On a couple of occasions, I've been tempted to bid on
Rohde & Schwarz instruments but hesitated to do
so because I have no experience in repairing their equipment.

I'm interested in any general comments regarding
availability of technical manuals and spare parts for
R&S equipment relative to Tektronix and Agilent
(Hewlett-Packard) instruments.

To some degree, we've been spoiled, er, we have
benefited by the relatively open technical culture
presented by Tektronix's and Hewlett-Packard's older
products. The rise of custom ICs and modular products
(e.g., power supplies), coupled with concern over
industrial espionage, has affected repairability of
their newer instruments, though.

Feel free to reply to me off-list if you wish and I'll
treat your comments as confidential.

Thanks, and 73--

Brad AA1IP


Re: Repairability of Rohde & Schwarz instruments?

Peter Gottlieb <hpnpilot@...>
 

Indeed. I will avoid any company that won't work with Dave.

On 2/10/2013 3:44 PM, Dave Daniel wrote:

That is a huge mark against them, IMO.

Dave

On 2/10/2013 1:42 PM, Artekmedia wrote:

Manuals can definitely be a problem..they are relatively scarce ( or VERY expensive when you can find them) and to this point they wont return emails of phone calls concerning the release of copyrights to make copies of manuals for units that are no longer supported.

Dave
ArtekManuals.com



On 2/10/2013 2:30 PM, Dave Daniel wrote:

I would be interested in any insight into R&S gear as well.

Dave


On 2/10/2013 1:10 PM, Brad Thompson wrote:

Hello--

On a couple of occasions, I've been tempted to bid on
Rohde & Schwarz instruments but hesitated to do
so because I have no experience in repairing their equipment.

I'm interested in any general comments regarding
availability of technical manuals and spare parts for
R&S equipment relative to Tektronix and Agilent
(Hewlett-Packard) instruments.

To some degree, we've been spoiled, er, we have
benefited by the relatively open technical culture
presented by Tektronix's and Hewlett-Packard's older
products. The rise of custom ICs and modular products
(e.g., power supplies), coupled with concern over
industrial espionage, has affected repairability of
their newer instruments, though.

Feel free to reply to me off-list if you wish and I'll
treat your comments as confidential.

Thanks, and 73--

Brad AA1IP
--
Dave Henderson
Manuals@ArtekManuals.com
www.Artekmanuals.com
PO Box 175
Welch,MN 55089
651-269-4265
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Re: Repairability of Rohde & Schwarz instruments?

Herbert
 

Hi Chris,

the quality of the equipment is good, but the support is XXX beep XXX.
The management policy is so stupid, that the service people ask clients
for a copy of older equipment, because years ago they had shreddered
all documentation papers ?!

Now what.... a good product and a stupid management which produces
a disabled support / service !

If, when ever you have a a R&S piece, your equipment has problems, you
need a friend, who has the docs or has a friend ....!

Try in the group
Rohde_Schwarz@...

and ........  good luck !

Herbert


Am 10.02.2013 21:16, schrieb cleyson@...:

 

I once had a scrapped R&S SMT02 sig gen, the RF leveller didn't
work properly and dropped the RF level 20dB, the attenuator was
suspected but found to be OK and there were also a few synthesizer
"out of lock" error messages on startup. The cheapest quote for
repair was £3000. The large LCD displays on the front of some R&S
sig gens are also prone to failure

No circuit diagrams available and I even asked Rohde & Schwarz
but they said send it to your nearest R&S dealer. Oh, and perhaps
more important, the close-in spectral purity was rubish.

Personally I wouldn't recommend R&S, stick to TEK and HP.

Chris

--- In TekScopes@..., Brad Thompson wrote:
>
> Hello--
>
> On a couple of occasions, I've been tempted to bid on
> Rohde & Schwarz instruments but hesitated to do
> so because I have no experience in repairing their equipment.
>
> I'm interested in any general comments regarding
> availability of technical manuals and spare parts for
> R&S equipment relative to Tektronix and Agilent
> (Hewlett-Packard) instruments.
>
> To some degree, we've been spoiled, er, we have
> benefited by the relatively open technical culture
> presented by Tektronix's and Hewlett-Packard's older
> products. The rise of custom ICs and modular products
> (e.g., power supplies), coupled with concern over
> industrial espionage, has affected repairability of
> their newer instruments, though.
>
> Feel free to reply to me off-list if you wish and I'll
> treat your comments as confidential.
>
> Thanks, and 73--
>
> Brad AA1IP
>



Re: TDS 744A Power Supply Issue - Any Ideas?

circuitsandcode
 

Latest status - ordered BU508AF parts from one of the houses that allows for qty <10. I got one to burn, one for replace, and a few spares for my local parts bin.

Since I cannot at the moment identify the skew of the SL-series thermistor used for inrush current protection (on the failed BU508A) - I'm going to skip replacing them and restuff the original parts.

Original cap replacement (8 caps) only found a few matches at the local supply store. So I'll replace what I can and leave the original parts for some.

--- In TekScopes@yahoogroups.com, "circuitsandcode" wrote:

I have been putting debug on the back burner as this scope is not in my critical path. As such, it sure helps when I get handed historical failure data on a closely related power supply.

Jose's power supply is not exactly the same as the 744's, but it's a closer relative than the 520. All of the pictures appeared to match 100% of the mechanical features. His failed Q9 exists on the 744 while it does not on the 520 (520 uses U12 instead).

One place where our supplies diverge is the protection circuitry. He shows RV (voltage protection) while the 744 uses RT (temperature / current surge protection). One note: the markings on the thermistors only show "SL" which is a series. Although one can narrow down the part by outer dimensions - there are multiple parts with the same dimensions. If I want to replace these I either need to do math, measure physical dimensions and guess, or characterize these parts on the assumption that at least one of the two still work. That is - unless BOMs of power supplies lacking schematics are available.

No matter ... back to the debug, I can shotgun with the best of them. I had already planned on removing loads off of 400V to try to isolate failures.

Removing Q9 and RT4 RT5 increased my previous 70V reading to 170V. Terminals of Q9 (out of circuit) measure 0.2V on diode check between CE. BC showing 0.4V. Appears failed.

The failure may have caused an overvoltage on downstream parts (parts on standby). I'll have to queue up more work -- slowly -- through next week.

One comment about the ESR measurements and the 5V/1kHz square wave: all caps are tested with this out of circuit.

Happy year of the snake.


--- In TekScopes@yahoogroups.com, Chin Siang Lim wrote:

Take a look at what the great Joe of Spain had done on his TDS524 power
supply and display:
http://www.jvgavila.com/tds524a.htm

Could you check the same BU power transistor?
cslim

94801 - 94820 of 182212