Topics

HP 9810A firmware board failure


Adam Jones
 

I have a unit with a bad  09810-66521 system firmware board.  

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


Adam Jones
 

HI Rik, 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

So....

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

I am open to suggestions!

Adam Jones
Windham, ME

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.



--
Adam Jones
Windham, ME


 

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So....

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME


Adam Jones
 

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

You only get a measurement in one direction, correct?

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

Adam Jones

Sent from my mobile. 

On Nov 8, 2018, at 10:29 AM, Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So....

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME


Steve Leibson
 

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve



On 11/8/2018 7:02 PM, Adam Jones wrote:
The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

You only get a measurement in one direction, correct?

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

Adam Jones

Sent from my mobile. 

On Nov 8, 2018, at 10:29 AM, Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So...

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME


-- 
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


Adam Jones
 

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

Sent from my mobile. 

On Nov 8, 2018, at 10:21 PM, Steve Leibson <steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve



On 11/8/2018 7:02 PM, Adam Jones wrote:
The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

You only get a measurement in one direction, correct?

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

Adam Jones

Sent from my mobile. 

On Nov 8, 2018, at 10:29 AM, Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So...

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME


-- 
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


Steve Leibson
 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve



On 11/8/2018 7:34 PM, Adam Jones wrote:
I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

Sent from my mobile. 

On Nov 8, 2018, at 10:21 PM, Steve Leibson <steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve



On 11/8/2018 7:02 PM, Adam Jones wrote:
The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

You only get a measurement in one direction, correct?

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

Adam Jones

Sent from my mobile. 

On Nov 8, 2018, at 10:29 AM, Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So...

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME


-- 
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

-- 
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


 

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So...

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME



-- 
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



-- 
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


Adam Jones
 

Well they likely took a hit and one is fried.  

I guess I’ll be waiting/looking for a spare board somewhere to revive this machine. 

Adam Jones

Sent from my mobile. 

On Nov 9, 2018, at 5:43 AM, Rik Bos <hp-fix@...> wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So...

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME



-- 
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



-- 
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


Adam Jones
 

I do have a two parts machine: 9820 and 9830A if someone might be interested in a trade for the board in need.  

The 9830 needs the power supply fixed as I have confirmed all the boards work in another machine.  The 9820 has an issue with one of the boards in the ROM/RAM box.  

Adam Jones

Sent from my mobile. 

On Nov 9, 2018, at 6:20 AM, Adam Jones <aj04062@...> wrote:

Well they likely took a hit and one is fried.  

I guess I’ll be waiting/looking for a spare board somewhere to revive this machine. 

Adam Jones

Sent from my mobile. 

On Nov 9, 2018, at 5:43 AM, Rik Bos <hp-fix@...> wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So...

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME



-- 
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



-- 
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


Steve Leibson
 

Note that I was definitely not advocating applying 5V to the board out of circuit. I was advocating measuring the 5V supply in circuit. I am sorry if that wasn't clear.

--Steve



On 11/9/2018 2:43 AM, Rik Bos wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So..

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME



-- 
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



-- 
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

-- 
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


 

You were clear, It was a warning to Adam.

As you probably know sourcing a TTL board with an external 5V isn’t a problem, but for the MOS boards (RAM. ROM) it can be a problem if not all the supplies are in place.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 16:17
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

Note that I was definitely not advocating applying 5V to the board out of circuit. I was advocating measuring the 5V supply in circuit. I am sorry if that wasn't clear.

--Steve

 

 

On 11/9/2018 2:43 AM, Rik Bos wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So..

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME




-- 
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




-- 
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



-- 
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


Steve Leibson
 

You're right Rik. Powering up any board with partial supplies is risky. Lots of boards have analog plus digital, with 5V (or 3.3V or 2.5V or 1.8V) plus the analog supply voltages. Powering these up with partial supplies is risky too.

--Steve



On 11/9/2018 8:28 AM, Rik Bos wrote:

You were clear, It was a warning to Adam.

As you probably know sourcing a TTL board with an external 5V isn’t a problem, but for the MOS boards (RAM. ROM) it can be a problem if not all the supplies are in place.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 16:17
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

Note that I was definitely not advocating applying 5V to the board out of circuit. I was advocating measuring the 5V supply in circuit. I am sorry if that wasn't clear.

--Steve

 

 

On 11/9/2018 2:43 AM, Rik Bos wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So..

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME




-- 
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




-- 
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



-- 
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

-- 
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


Adam Jones
 

If one of the ROMs is Toast is there any solution other than the same board?

Adam Jones

Sent from my mobile. 

On Nov 9, 2018, at 11:31 AM, Steve Leibson <steven.leibson@...> wrote:

You're right Rik. Powering up any board with partial supplies is risky. Lots of boards have analog plus digital, with 5V (or 3.3V or 2.5V or 1.8V) plus the analog supply voltages. Powering these up with partial supplies is risky too.

--Steve



On 11/9/2018 8:28 AM, Rik Bos wrote:

You were clear, It was a warning to Adam.

As you probably know sourcing a TTL board with an external 5V isn’t a problem, but for the MOS boards (RAM. ROM) it can be a problem if not all the supplies are in place.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 16:17
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

Note that I was definitely not advocating applying 5V to the board out of circuit. I was advocating measuring the 5V supply in circuit. I am sorry if that wasn't clear.

--Steve

 

 

On 11/9/2018 2:43 AM, Rik Bos wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So..

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME




-- 
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




-- 
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



-- 
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

-- 
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


 

Yes, or designing a new board using modern parts.

It shouldn’t be very difficult because the board only houses the rom’s

You’ll need some address translation and may some level shifters.

16K is all you need.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: vrijdag 9 november 2018 17:46
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

If one of the ROMs is Toast is there any solution other than the same board?

Adam Jones

 

Sent from my mobile. 


On Nov 9, 2018, at 11:31 AM, Steve Leibson <steven.leibson@...> wrote:

You're right Rik. Powering up any board with partial supplies is risky. Lots of boards have analog plus digital, with 5V (or 3.3V or 2.5V or 1.8V) plus the analog supply voltages. Powering these up with partial supplies is risky too.

--Steve

 

 

On 11/9/2018 8:28 AM, Rik Bos wrote:

You were clear, It was a warning to Adam.

As you probably know sourcing a TTL board with an external 5V isn’t a problem, but for the MOS boards (RAM. ROM) it can be a problem if not all the supplies are in place.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 16:17
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

Note that I was definitely not advocating applying 5V to the board out of circuit. I was advocating measuring the 5V supply in circuit. I am sorry if that wasn't clear.

--Steve

 

 

On 11/9/2018 2:43 AM, Rik Bos wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So..

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME





-- 
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





-- 
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




-- 
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



-- 
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


Adam Jones
 

Hmmm.  I guess I’ll have to study Tony’s schematics closer to see how to design from scratch, unless you have a suggestion.  

Adam Jones

Sent from my mobile. 

On Nov 9, 2018, at 12:18 PM, Rik Bos <hp-fix@...> wrote:

Yes, or designing a new board using modern parts.

It shouldn’t be very difficult because the board only houses the rom’s

You’ll need some address translation and may some level shifters.

16K is all you need.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: vrijdag 9 november 2018 17:46
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

If one of the ROMs is Toast is there any solution other than the same board?

Adam Jones

 

Sent from my mobile. 


On Nov 9, 2018, at 11:31 AM, Steve Leibson <
steven.leibson@...> wrote:

You're right Rik. Powering up any board with partial supplies is risky. Lots of boards have analog plus digital, with 5V (or 3.3V or 2.5V or 1.8V) plus the analog supply voltages. Powering these up with partial supplies is risky too.

--Steve

 

 

On 11/9/2018 8:28 AM, Rik Bos wrote:

You were clear, It was a warning to Adam.

As you probably know sourcing a TTL board with an external 5V isn’t a problem, but for the MOS boards (RAM. ROM) it can be a problem if not all the supplies are in place.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 16:17
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

Note that I was definitely not advocating applying 5V to the board out of circuit. I was advocating measuring the 5V supply in circuit. I am sorry if that wasn't clear.

--Steve

 

 

On 11/9/2018 2:43 AM, Rik Bos wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So..

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME





-- 
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





-- 
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




-- 
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



-- 
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


Kuba Ober
 

I wonder if the ROMs are slow enough that a fast microcontroller with flash eprom inside could emulate the ROM. The benefit is USB connectivity for reflashing, and it’s essentially free (well, for the cost of the connector). Off the top of my head, the smallest XMOS MCU would be plenty fast for this application, and it’s a single-chip solution, bar some voltage translation. Other single-cycle microcontrollers with fast clocks would probably work as well, perhaps if the clock was synchronized to the bus clock – and many have the requisite PLLs included. On some micro controllers, the DMA could be coaxed to move the data without any software involvement other than configuration: a DMA trigger would first copy GPIO inputs (two bytes) to another channel’s DMA address register, and then that other channel would do the transfer from memory to GPIO output byte. I’ve done such “hacks” before and they can work admirably.  

Cheers, Kuba

9 nov. 2018 kl. 12:23 skrev Adam Jones <aj04062@...>:

Hmmm.  I guess I’ll have to study Tony’s schematics closer to see how to design from scratch, unless you have a suggestion.  

Adam Jones

Sent from my mobile. 

On Nov 9, 2018, at 12:18 PM, Rik Bos <hp-fix@...> wrote:

Yes, or designing a new board using modern parts.

It shouldn’t be very difficult because the board only houses the rom’s

You’ll need some address translation and may some level shifters.

16K is all you need.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: vrijdag 9 november 2018 17:46
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

If one of the ROMs is Toast is there any solution other than the same board?

Adam Jones

 

Sent from my mobile. 


On Nov 9, 2018, at 11:31 AM, Steve Leibson <
steven.leibson@...> wrote:

You're right Rik. Powering up any board with partial supplies is risky. Lots of boards have analog plus digital, with 5V (or 3.3V or 2.5V or 1.8V) plus the analog supply voltages. Powering these up with partial supplies is risky too.

--Steve

 

 

On 11/9/2018 8:28 AM, Rik Bos wrote:

You were clear, It was a warning to Adam.

As you probably know sourcing a TTL board with an external 5V isn’t a problem, but for the MOS boards (RAM. ROM) it can be a problem if not all the supplies are in place.

 

-Rik

 

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 16:17
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

Note that I was definitely not advocating applying 5V to the board out of circuit. I was advocating measuring the 5V supply in circuit. I am sorry if that wasn't clear.

--Steve

 

 

On 11/9/2018 2:43 AM, Rik Bos wrote:

Just putting 5V to the rom board is a bad idea, it could do some damage to your rom’s.

The caps are used for noise suppression and are tantalums, those fail in just one way they short Rs<1 Ohm.

A measured value of 2.5k is well in spec.

Please, keep in mind the boards are susceptible for ESD.(ROM and RAM boards)

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Steve Leibson
Verzonden: vrijdag 9 november 2018 4:54
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

You can temporarily solder a couple of wires (5V and ground) to the board to create accessibility, Adam.

--Steve

 

 

On 11/8/2018 7:34 PM, Adam Jones wrote:

I have no way to check the voltage when the board is plugged in.  It is inaccessible.  

 

I suppose I could apply 5v using my power supply to to proper edge connectors.  

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:21 PM, Steve Leibson <
steven.leibson@...> wrote:

At the risk of being proven to be the ignorant soul I am, have you checked the 5V supply (across the caps) with the board plugged in? If a bypass cap is bad, it will drag down the supply. I don't have a schematic, but is there a big bulk bypass electrolytic cap on the board? That's always my first suspect, especially for a board full of parts that are pushing half a century.

The same supply sag might happen with a bad ROM or any other IC on the board, but it's less likely.

--Steve

 

 

On 11/8/2018 7:02 PM, Adam Jones wrote:

The right most cap (looking at the component side of the board) settled at about 2.5k ohm. 

 

You only get a measurement in one direction, correct?

 

Comparing the measurement between boards (Jack’s works) and mine don’t produce hugely different values.  

 

I do have Peak Atlas LCR40, DCA55 and ESR70 analyzers.  

 

Adam Jones

 

Sent from my mobile. 


On Nov 8, 2018, at 10:29 AM, Rik Bos <
hp-fix@...> wrote:

Hi Adam,

 

Checking the caps is easy, measure with a resistance meter over the caps.

Resistance should be between 1 – 2k (1000-2000 ohm).

If you measure a short probably the cap shorts, so remove the cap and measure again if the short stays, one of the ROM’s is bad.

The second cap filters the bias voltage of the rom, if this isn’t the right voltage the rom won’t  work.

The PCB is a rather simple design and there is not much chance something is wrong with it.

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: donderdag 8 november 2018 1:40
Aan: VintHPcom@groups.io
Onderwerp: Re: [VintHPcom] HP 9810A firmware board failure

 

HI Rik, 

 

Jack Rubin was so kind to loan me a set of boards to try.  I restored a 9810 earlier this year and was looking to fire it up a few weeks ago.  When it started, all that it did was come up with the display at all 0s.  As soon as any key was depressed, the display went blank.

 

I pulled all cards and cleaned the contacts with an eraser and alcohol.  Still no difference.  When I got Jack's boards is when I started to swap and by luck the first one I tried, 09810-66521, revived the machine.  I cleaned and put back the old board and it still didn't work. 

 

So..

 

I am NOT an EE.  I don't have the expertise to diagnose the problem down to the component level.  My simple ME/MBA mind is left to conclude that either the caps, resistors or ROMs on the board have failed.  I hope it is the replaceable items!  Perhaps it is a bad solder joint impacting signals?  I have not tried to rework the board at all..

 

I am open to suggestions!

 

Adam Jones

Windham, ME

 

On Wed, Nov 7, 2018 at 3:57 PM Rik Bos <hp-fix@...> wrote:

Hi Adam,

 

Could you tell us how you came to the conclusion of the defective ROM board?

I’ve never encountered a defective rom board, and ‘loose’ rom boards being very rare ..

 

-Rik

 

Van: VintHPcom@groups.io <VintHPcom@groups.io> Namens Adam Jones
Verzonden: woensdag 7 november 2018 18:41
Aan: VintHPcom@groups.io
Onderwerp: [VintHPcom] HP 9810A firmware board failure

 

I have a unit with a bad  09810-66521 system firmware board.  

 

I have not replaced the two caps or resistors yet but was wondering if anyone might have an original for sale. 

Adam Jones

Sent from my mobile.


 

--

Adam Jones
Windham, ME





-- 
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





-- 
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




-- 
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



-- 
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


Chris Hanson
 

On Nov 9, 2018, at 9:18 AM, Rik Bos <hp-fix@...> wrote:

Yes, or designing a new board using modern parts.

It shouldn’t be very difficult because the board only houses the rom’s

You’ll need some address translation and may some level shifters.

16K is all you need.


This would be awesome in any case, as a way to add more flexibility to old systems.

I have a 9000/332 on the way and would like to have a ROM board to use it for a dedicated task… If it used flash and could be reprogrammed via USB, so much the better, but even plain EPROM would be great.

  — Chris


Adam Jones
 

Would any of you be willing to sketch out what I’d have to buy/make to do the suggested replacement board?  

Adam Jones

Sent from my mobile. 

On Nov 9, 2018, at 3:05 PM, Chris Hanson <cmhanson@...> wrote:

On Nov 9, 2018, at 9:18 AM, Rik Bos <hp-fix@...> wrote:

Yes, or designing a new board using modern parts.

It shouldn’t be very difficult because the board only houses the rom’s

You’ll need some address translation and may some level shifters.

16K is all you need.


This would be awesome in any case, as a way to add more flexibility to old systems.

I have a 9000/332 on the way and would like to have a ROM board to use it for a dedicated task… If it used flash and could be reprogrammed via USB, so much the better, but even plain EPROM would be great.

  — Chris