¿ªÔÆÌåÓý

Date

Re: Test Equipment where battery failure causes SERIOUS problems

 

The 859X series spectrum analyzers loose: band leveling offsets, attenuator corrections, and clock corrections if the memory battery dies. There is at least a procedure to copy these down from the operator interface so they can be reloaded in event of failure.?
-Kelly


On Wednesday, February 17, 2016 2:02 AM, "Peter Hansen oz1lpr@... [hp_agilent_equipment]" wrote:


?
Hello David?I think the HP 8756 Scalar analyzer?Looses all the Channel calibration data if the battery is lost. This requires?programming through a HP computer with obsolete software.
best regards Peter Hansen
?

To: hp_agilent_equipment@...
From: hp_agilent_equipment@...
Date: Tue, 16 Feb 2016 21:39:40 +0000
Subject: [hp_agilent_equipment] Re: Test Equipment where battery failure causes SERIOUS problems

?

On 16 February 2016 at 21:27, Dr. David Kirkby (Kirkby Microwave Ltd) <drkirkby@...> wrote:


2) HP 3457A 6.5 digit multimeter


whilst not so catastrophic, a report I read recently on one of the newsgroups from someone, said he sent a 3457A in for calibration, and the company was not happy as the failure of the battery added an hour to the calibration time. They were going to charge for this, but in the end they did not.

Just to clarify, the extra hour was not for replacing the battery - the owner had already done that. The extra hour was for the fact every range needed zeroing and setting to full scale.?




Re: HP 3325A

 

If its any consolation,I have two 3325As in regular use. One has had this same fault since I owned it and the other appears to have developed the fault in th last five to ten weeks. I cannot verify the serial numbers at this stage as Im away from the lab at present. I have been following the thread with interest.


Pete


Re: Test Equipment where battery failure causes SERIOUS problems

 

¿ªÔÆÌåÓý

Hello David?I think the HP 8756 Scalar analyzer?Looses all the Channel calibration data if the battery is lost. This requires?programming through a HP computer with obsolete software.
best regards Peter Hansen
?

To: hp_agilent_equipment@...
From: hp_agilent_equipment@...
Date: Tue, 16 Feb 2016 21:39:40 +0000
Subject: [hp_agilent_equipment] Re: Test Equipment where battery failure causes SERIOUS problems

?

On 16 February 2016 at 21:27, Dr. David Kirkby (Kirkby Microwave Ltd) <drkirkby@...> wrote:


2) HP 3457A 6.5 digit multimeter


whilst not so catastrophic, a report I read recently on one of the newsgroups from someone, said he sent a 3457A in for calibration, and the company was not happy as the failure of the battery added an hour to the calibration time. They were going to charge for this, but in the end they did not.

Just to clarify, the extra hour was not for replacing the battery - the owner had already done that. The extra hour was for the fact every range needed zeroing and setting to full scale.?



Re: 8590E Video Display problem

 

I have noticed that many pieces of HP equipment have an electrolytic
capacitor that goes from the wiper of the intensity pot to ground.

The purpose of the cap is to cause the instrument to start with the
beam forced off. This protects the phosphor during those moments
while the power supplies are coming up to voltage, and various
amplifiers may be operating in out of bounds conditions.

When the capacitor becomes leaky, it can draw enough current that it
keeps the intensity turned off. The condition improves somewhat as
the instrument warms up and the capacitor charges.

-Chuck Harris

Artek Manuals manuals@... [hp_agilent_equipment] wrote:

On 2/16/2016 5:27 PM, pbbob426@... [hp_agilent_equipment] wrote:
I have an HP 8590E in which there is no video on initial power up. But
consistently, if I shut the 8590E down anytime after about 2 minutes and
turn it again, the display is perfect - until the next cold start.


Anyone have any ideas what may be causing this?
Bad cap somewhere...holding an address line down on a cold start ...then
on a warm start the cap is feeling better and lets the address line come
up faster


Re: HP 3325A What ROMS?

 

Sorry to connect up to this thread. tried to make a new one but Yahoo no longer recognizes my id and wont let me post
new thread
Been following the 3325A threads as I think I have a ROM issue with mine, but have looked at all the referenced
threads and cant find mine there
My printed manuals including the Hp cross references are currently under a 4 ft pile of manuals etc after a 6 shelved cheap bookshelf collapsed and threw everything on the floor ... had been Ok for the last 3 years, but gave up under the weight last night, so apologies for asking stuff I may have been able to find otherwise... its over 40Deg C in there at the moment as were having a continual heatwave her in West Australia
and I cant even breath properly in that room.right now

3325A S/N 1748A03039 OPTION 1 Bought at local auction 5 years ago

4 X ROMS soldered in Probably Synertec (Large square "S")

U1
7941E
C51030
Hp No 1818-0702

U2
7932E
C51031
Hp No 1818 -0703

U3
8007E
C51032
Hp No 1818 -0704

U4
7952E
C51243
Hp No 1818-9705

The "5" after the C is definitely a Five, not a Y

Q: can you point me to where I can find mod info for these chips replacements please?
Have downloaded ( start Jun 3rd 2013) 3325A collection as directed , but don't see anything relevant to my chip set there

Symptoms are: crazy randomized LED display constantly randomly repeating.

Previous work done:
Replaced On/Off switch
Replaced all ribbon interconnects with made up ones as originals separated (All connections checked out OK ....big job)
Replaced a (wire wound!!) output resistor from a previous "repair" with original HF type.
All PSU voltages correct with ripple within specs
Had been working fine until a few months ago
Thanks for your time

John


Re: Soldering recommendation

 

I read somewhere that heat is used to soften Cyanoacrylate and alcohol is used to dissolve it so that you can separate the two pieces.

On 2016-Feb-16 10:11 PM, Peter Gottlieb hpnpilot@... [hp_agilent_equipment] wrote:
I may do that. Tried the hot air, too crude even with a very small tip, and it
started softening the glue I used to keep everything stable.

Peter


Re: HP8593A Power Supply repair

 

Hi Ted,

Hand made diagrams sent to your personal Email.
Wish you success.

Regards/Roumen
LZ3RV
Sofia, Bulgaria


Re: Soldering recommendation

PeteM
 

It melts around 275 deg +/-

Pete wa2odo



¡­ sent from Android on 4G¡­

On Feb 16, 2016 10:43 PM, "Peter Gottlieb hpnpilot@... [hp_agilent_equipment]" <hp_agilent_equipment@...> wrote:

?

Indium solder, haven't heard of that in a while!? I shall try and find some.?


Peter

On Feb 16, 2016, at 10:37 PM, PeteM pmanfre@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

?

Try some indium solder and if necessary a needle heated with a soldering iron. I have repaired accutron coils with it as well as other watch coils.

Pete

¡­ sent from Android on 4G¡­

On Feb 16, 2016 10:12 PM, "Peter Gottlieb hpnpilot@... [hp_agilent_equipment]" <hp_agilent_equipment@...> wrote:
?

I may do that. Tried the hot air, too crude even with a very small tip, and it
started softening the glue I used to keep everything stable.

Peter

On 2/16/2016 9:22 PM, EB4APL eb4apl@... [hp_agilent_equipment] wrote:
>
> Why don't you try with silver conductive paint? Auto shops use it for
> repairing rear window heaters and some are advertised for repairing printed
> circuit boards. probably you need to glue the problem area to a stiff back
> before repairing.
> Or if the flex circuit is heath resistant you could use the solder paste with
> a hot air station.
>
> Just an idea,
> Ignacio
>
>
>
> El 17/02/2016 a las 3:09, Peter Gottlieb hpnpilot@...
> [hp_agilent_equipment] escribi¨®:
>>
>> I have a challenging soldering job and am looking for advice from someone who's
>> tackled something like it before.
>>
>> I have a modern high-end device which has a complex and unobtainable custom LCD
>> display. This display connects via a flex circuit to a connector on the main
>> board.
>>
>> Unfortunately, the mechanical design is not great and where the flex circuit
>> attaches to the LCD glass there is no strain relief so a couple of flexes and
>> several traces broke. These traces are approximately 4 mils wide, spaced 4 mils
>> apart. Under a stereo microscope I was able, using a new X-acto knife and VERY
>> gently, scrape off the insulation on each side of the broken traces. I secured
>> under the movable part with some cyanoacrilate. I now need to solder perhaps a
>> wire across the broken traces. Using some surface mount paste (looks like BBs
>> under the microscope) I managed to tin the traces but my soldering tip looks
>> like I'm using a copper roofing iron, and that's after I sharpened it to what
>> looked like a super fine point. Heck, at 40X even a pin looks rounded. #30
>> wirewrap wire is far too large but I did find some perfect wire strands from
>> some superflex silicone RC wire. It reads 3.5 mils dia on my micrometer.
>>
>> So, this seems like a tough job but I did get one piece on after several tries.
>> Has anyone who has successfully done something this have any pointers? Is there
>> an iron meant for this kind of micro work? Things I should or shouldn't do?
>>
>> Peter
>>
>
>
> Este correo electr¨®nico se ha enviado desde un equipo libre de virus y
> protegido por Avast.
> <>
>
>




Re: Soldering recommendation

 

¿ªÔÆÌåÓý

Indium solder, haven't heard of that in a while! ?I shall try and find some.?


Peter

On Feb 16, 2016, at 10:37 PM, PeteM pmanfre@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

?

Try some indium solder and if necessary a needle heated with a soldering iron. I have repaired accutron coils with it as well as other watch coils.

Pete

¡­ sent from Android on 4G¡­

On Feb 16, 2016 10:12 PM, "Peter Gottlieb hpnpilot@... [hp_agilent_equipment]" <hp_agilent_equipment@...> wrote:
?

I may do that. Tried the hot air, too crude even with a very small tip, and it
started softening the glue I used to keep everything stable.

Peter

On 2/16/2016 9:22 PM, EB4APL eb4apl@... [hp_agilent_equipment] wrote:
>
> Why don't you try with silver conductive paint? Auto shops use it for
> repairing rear window heaters and some are advertised for repairing printed
> circuit boards. probably you need to glue the problem area to a stiff back
> before repairing.
> Or if the flex circuit is heath resistant you could use the solder paste with
> a hot air station.
>
> Just an idea,
> Ignacio
>
>
>
> El 17/02/2016 a las 3:09, Peter Gottlieb hpnpilot@...
> [hp_agilent_equipment] escribi¨®:
>>
>> I have a challenging soldering job and am looking for advice from someone who's
>> tackled something like it before.
>>
>> I have a modern high-end device which has a complex and unobtainable custom LCD
>> display. This display connects via a flex circuit to a connector on the main
>> board.
>>
>> Unfortunately, the mechanical design is not great and where the flex circuit
>> attaches to the LCD glass there is no strain relief so a couple of flexes and
>> several traces broke. These traces are approximately 4 mils wide, spaced 4 mils
>> apart. Under a stereo microscope I was able, using a new X-acto knife and VERY
>> gently, scrape off the insulation on each side of the broken traces. I secured
>> under the movable part with some cyanoacrilate. I now need to solder perhaps a
>> wire across the broken traces. Using some surface mount paste (looks like BBs
>> under the microscope) I managed to tin the traces but my soldering tip looks
>> like I'm using a copper roofing iron, and that's after I sharpened it to what
>> looked like a super fine point. Heck, at 40X even a pin looks rounded. #30
>> wirewrap wire is far too large but I did find some perfect wire strands from
>> some superflex silicone RC wire. It reads 3.5 mils dia on my micrometer.
>>
>> So, this seems like a tough job but I did get one piece on after several tries.
>> Has anyone who has successfully done something this have any pointers? Is there
>> an iron meant for this kind of micro work? Things I should or shouldn't do?
>>
>> Peter
>>
>
>
> Este correo electr¨®nico se ha enviado desde un equipo libre de virus y
> protegido por Avast.
> <>
>
>




Re: Soldering recommendation

PeteM
 

Try some indium solder and if necessary a needle heated with a soldering iron. I have repaired accutron coils with it as well as other watch coils.

Pete

¡­ sent from Android on 4G¡­

On Feb 16, 2016 10:12 PM, "Peter Gottlieb hpnpilot@... [hp_agilent_equipment]" <hp_agilent_equipment@...> wrote:

?

I may do that. Tried the hot air, too crude even with a very small tip, and it
started softening the glue I used to keep everything stable.

Peter

On 2/16/2016 9:22 PM, EB4APL eb4apl@... [hp_agilent_equipment] wrote:
>
> Why don't you try with silver conductive paint? Auto shops use it for
> repairing rear window heaters and some are advertised for repairing printed
> circuit boards. probably you need to glue the problem area to a stiff back
> before repairing.
> Or if the flex circuit is heath resistant you could use the solder paste with
> a hot air station.
>
> Just an idea,
> Ignacio
>
>
>
> El 17/02/2016 a las 3:09, Peter Gottlieb hpnpilot@...
> [hp_agilent_equipment] escribi¨®:
>>
>> I have a challenging soldering job and am looking for advice from someone who's
>> tackled something like it before.
>>
>> I have a modern high-end device which has a complex and unobtainable custom LCD
>> display. This display connects via a flex circuit to a connector on the main
>> board.
>>
>> Unfortunately, the mechanical design is not great and where the flex circuit
>> attaches to the LCD glass there is no strain relief so a couple of flexes and
>> several traces broke. These traces are approximately 4 mils wide, spaced 4 mils
>> apart. Under a stereo microscope I was able, using a new X-acto knife and VERY
>> gently, scrape off the insulation on each side of the broken traces. I secured
>> under the movable part with some cyanoacrilate. I now need to solder perhaps a
>> wire across the broken traces. Using some surface mount paste (looks like BBs
>> under the microscope) I managed to tin the traces but my soldering tip looks
>> like I'm using a copper roofing iron, and that's after I sharpened it to what
>> looked like a super fine point. Heck, at 40X even a pin looks rounded. #30
>> wirewrap wire is far too large but I did find some perfect wire strands from
>> some superflex silicone RC wire. It reads 3.5 mils dia on my micrometer.
>>
>> So, this seems like a tough job but I did get one piece on after several tries.
>> Has anyone who has successfully done something this have any pointers? Is there
>> an iron meant for this kind of micro work? Things I should or shouldn't do?
>>
>> Peter
>>
>
>
> Este correo electr¨®nico se ha enviado desde un equipo libre de virus y
> protegido por Avast.
> <>
>
>


Re: Soldering recommendation

 

I may do that. Tried the hot air, too crude even with a very small tip, and it started softening the glue I used to keep everything stable.

Peter

On 2/16/2016 9:22 PM, EB4APL eb4apl@... [hp_agilent_equipment] wrote:

Why don't you try with silver conductive paint? Auto shops use it for repairing rear window heaters and some are advertised for repairing printed circuit boards. probably you need to glue the problem area to a stiff back before repairing.
Or if the flex circuit is heath resistant you could use the solder paste with a hot air station.

Just an idea,
Ignacio



El 17/02/2016 a las 3:09, Peter Gottlieb hpnpilot@... [hp_agilent_equipment] escribi¨®:

I have a challenging soldering job and am looking for advice from someone who's
tackled something like it before.

I have a modern high-end device which has a complex and unobtainable custom LCD
display. This display connects via a flex circuit to a connector on the main board.

Unfortunately, the mechanical design is not great and where the flex circuit
attaches to the LCD glass there is no strain relief so a couple of flexes and
several traces broke. These traces are approximately 4 mils wide, spaced 4 mils
apart. Under a stereo microscope I was able, using a new X-acto knife and VERY
gently, scrape off the insulation on each side of the broken traces. I secured
under the movable part with some cyanoacrilate. I now need to solder perhaps a
wire across the broken traces. Using some surface mount paste (looks like BBs
under the microscope) I managed to tin the traces but my soldering tip looks
like I'm using a copper roofing iron, and that's after I sharpened it to what
looked like a super fine point. Heck, at 40X even a pin looks rounded. #30
wirewrap wire is far too large but I did find some perfect wire strands from
some superflex silicone RC wire. It reads 3.5 mils dia on my micrometer.

So, this seems like a tough job but I did get one piece on after several tries.
Has anyone who has successfully done something this have any pointers? Is there
an iron meant for this kind of micro work? Things I should or shouldn't do?

Peter

Este correo electr¨®nico se ha enviado desde un equipo libre de virus y protegido por Avast.
www.avast.com <>


Re: Soldering recommendation

 

Hi Peter



Boy, I¡¯d like to know the same thing! One of the things I tried (unsuccessfully) not too long ago was to solder a broken wire on a coil of an Accutron (tuning fork) watch. I wasn¡¯t successful, and I know firsthand how that solder past looks under the microscope!

It¡¯s definitely NOT EASY!



Daun



Daun E. Yeagley, II, N8ASB



From: hp_agilent_equipment@... [mailto:hp_agilent_equipment@...]
Sent: Tuesday, February 16, 2016 9:09 PM
To: hp_agilent_equipment@...
Subject: [hp_agilent_equipment] Soldering recommendation





I have a challenging soldering job and am looking for advice from someone who's
tackled something like it before.

I have a modern high-end device which has a complex and unobtainable custom LCD
display. This display connects via a flex circuit to a connector on the main board.

Unfortunately, the mechanical design is not great and where the flex circuit
attaches to the LCD glass there is no strain relief so a couple of flexes and
several traces broke. These traces are approximately 4 mils wide, spaced 4 mils
apart. Under a stereo microscope I was able, using a new X-acto knife and VERY
gently, scrape off the insulation on each side of the broken traces. I secured
under the movable part with some cyanoacrilate. I now need to solder perhaps a
wire across the broken traces. Using some surface mount paste (looks like BBs
under the microscope) I managed to tin the traces but my soldering tip looks
like I'm using a copper roofing iron, and that's after I sharpened it to what
looked like a super fine point. Heck, at 40X even a pin looks rounded. #30
wirewrap wire is far too large but I did find some perfect wire strands from
some superflex silicone RC wire. It reads 3.5 mils dia on my micrometer.

So, this seems like a tough job but I did get one piece on after several tries.
Has anyone who has successfully done something this have any pointers? Is there
an iron meant for this kind of micro work? Things I should or shouldn't do?

Peter





[Non-text portions of this message have been removed]


Re: Soldering recommendation

 

¿ªÔÆÌåÓý

Why don't you try with silver conductive paint? Auto shops use it for repairing rear window heaters and some are advertised for repairing printed circuit boards. probably you need to glue the problem area to a stiff back before repairing.
Or if the flex circuit is heath resistant you could use the solder paste with a hot air station.

Just an idea,
Ignacio



El 17/02/2016 a las 3:09, Peter Gottlieb hpnpilot@... [hp_agilent_equipment] escribi¨®:
?

I have a challenging soldering job and am looking for advice from someone who's
tackled something like it before.

I have a modern high-end device which has a complex and unobtainable custom LCD
display. This display connects via a flex circuit to a connector on the main board.

Unfortunately, the mechanical design is not great and where the flex circuit
attaches to the LCD glass there is no strain relief so a couple of flexes and
several traces broke. These traces are approximately 4 mils wide, spaced 4 mils
apart. Under a stereo microscope I was able, using a new X-acto knife and VERY
gently, scrape off the insulation on each side of the broken traces. I secured
under the movable part with some cyanoacrilate. I now need to solder perhaps a
wire across the broken traces. Using some surface mount paste (looks like BBs
under the microscope) I managed to tin the traces but my soldering tip looks
like I'm using a copper roofing iron, and that's after I sharpened it to what
looked like a super fine point. Heck, at 40X even a pin looks rounded. #30
wirewrap wire is far too large but I did find some perfect wire strands from
some superflex silicone RC wire. It reads 3.5 mils dia on my micrometer.

So, this seems like a tough job but I did get one piece on after several tries.
Has anyone who has successfully done something this have any pointers? Is there
an iron meant for this kind of micro work? Things I should or shouldn't do?

Peter



Este correo electr¨®nico se ha enviado desde un equipo libre de virus y protegido por Avast.


Re: HP DVM / DMM technological history

 

Also the 3421A Data Acquisition Unit has voltage input terminals on the front panel IIRC.

On Feb 17, 2016, at 2:39 PM, Jeremy Nichols jn6wfo@... [hp_agilent_equipment] wrote:



Don't forget the 5265A Digital Voltmeter plug-in for the 5245-series counters!

Jeremy
N6WFO


Soldering recommendation

 

I have a challenging soldering job and am looking for advice from someone who's tackled something like it before.

I have a modern high-end device which has a complex and unobtainable custom LCD display. This display connects via a flex circuit to a connector on the main board.

Unfortunately, the mechanical design is not great and where the flex circuit attaches to the LCD glass there is no strain relief so a couple of flexes and several traces broke. These traces are approximately 4 mils wide, spaced 4 mils apart. Under a stereo microscope I was able, using a new X-acto knife and VERY gently, scrape off the insulation on each side of the broken traces. I secured under the movable part with some cyanoacrilate. I now need to solder perhaps a wire across the broken traces. Using some surface mount paste (looks like BBs under the microscope) I managed to tin the traces but my soldering tip looks like I'm using a copper roofing iron, and that's after I sharpened it to what looked like a super fine point. Heck, at 40X even a pin looks rounded. #30 wirewrap wire is far too large but I did find some perfect wire strands from some superflex silicone RC wire. It reads 3.5 mils dia on my micrometer.

So, this seems like a tough job but I did get one piece on after several tries. Has anyone who has successfully done something this have any pointers? Is there an iron meant for this kind of micro work? Things I should or shouldn't do?

Peter


Service Training Mamual for HP 8566 / 8568

 

Would anyone have any interest in my Service Training manual for the HP 8566A/B and 8568A/B?


This is NOT the service guide but rather a thick binder covering the circuit description with some schematics. This book was used during my service training at a two-week seminar at HP's Rohnert Park facility for these models.?


Please contact me off-list if interested.


$ 50 + $ 20 shipping



Steve


Re: HP DVM / DMM technological history

 

¿ªÔÆÌåÓý

Don't forget the 5265A Digital Voltmeter plug-in for the 5245-series counters!

Jeremy
N6WFO


On 2/16/2016 6:00 AM, d.garrido@... [hp_agilent_equipment] wrote:

?

Hello All,


I am doing a bit of research to accomplish a comprehensive understanding of the DVM / DMM technology from the late fifties and early sixties into the 90's. ?I have come up with what I think is a list that covers the models I should be looking into. ?Are there any more digital meters that should be added?


405

2401

2402

3435

3440

3450

3455

3456

3460

3465

3490


Cheers,


David



Re: HP8593A Power Supply repair

John
 

see msg# 67510 in the group messages..

Regards John

On 17-Feb-16 5:00:31 AM, newsong777@... [hp_agilent_equipment] (hp_agilent_equipment@...) wrote:
Roumen,
I would like to have a copy of the power supply schematics if it is possible. My HP8591A has the low 5.2 volt supply problem that others have mentioned. I am very experienced in this type of electronics and I would like to find a solution that is lasting and that I can share with others.
We have a family friend in Burgas and relatives in Russia, we are in the US.

Ted
Posted by: newsong777@...

Reply via web post[Links to ]
???

Reply to sender [Links to mailto:newsong777@...?subject=Re%3A%20HP8593A%20Power%20Supply%20repair]
???

Reply to group [Links to mailto:hp_agilent_equipment@...?subject=Re%3A%20HP8593A%20Power%20Supply%20repair]
???


HP 3325A ROM Replacement

 


I thought I would summarize a somewhat meandering thread.

I¡¯ve received the Artek manual and it is great!?

It appears I do have a failing ROM IC.?

As time went by HP changed from 4 4k*8 chips to 2 8k*8 chips and there is a way to jumper some boards to tell it which is installed.? (Joe: is that just the A/B jumpers near U5, or is it more than that?).? Apparently there are even some 3325a¡¯s with 3 ROM ics.

The HP nano-processor only has 11 address lines for a 12 bit space and so they played games to extract the 12 bit.? In the 4-chip solution, each chip has 2 select pins which are used in such a way as to provide the top 2 most significant bits.

Thus far, I have not found a 4k*8 EPROM or EEPROM that is pin-compatible with the original Synertek Sy2332/Motorola MCM88A332 masked ROM.? The TMS2532 are almost right, but lack the second select pin. [I keep seeing this listed even in historical literature as pin-compatible, but it is not according to the data sheets.? I¡¯ve seen this so many places that I wonder if the datasheets are wrong and pin 20 can be used as a second select.]

The original 2-IC solution used the Motorola MCM68764C EEPROM.? A later version of that chip? is the Motorola MCM68766.? Joe has previously extracted the 2-IC ROM program.? I would guess that the 4-IC data is the same, just split between chips.? I also think the data is the same independent of options as otherwise the signature analysis info would have to change between machines, and it does not.

My repair options include:


4 IC¡¯s.? This looks to require some extra glue logic to decode the second select unless a pin-compatible EEPROM can be found.? It would also require me to extract my data or split the existing 2-IC data.

2 IC¡¯s.? This only requires some jumper changes and the ROM program is already available.

1 IC solution.? Because the 3325a already decodes the 2 select pins as if they¡¯re address pins, this would only require a simple pin-remapping board for the new IC.

Option B looks like the obvious choice except that I have so far only been able to find used replacement EEPROMs and I wonder about the longevity of those.

I¡¯d also like to help the next person that needs to fix the ROM in a 3325a, and that argues for Option C.? Once option C is chosen almost any parallel ROM can be used and I¡¯m seeing some flash-ROM with a listed lifetime of 100+ years.

Does anyone have a favorite 16k*8 EEPROM ic that is common and likely to be available for a few more years?


Re: 8590E Video Display problem

 

Depending on the model the 8590 series video displays have different horizontal sweep rates. The video displays are externally identical but the 8590A has a lower sweep rate (15,750 Hz?) than the 8590L and I assume your 8590E (19KHz?). A horizontal oscillator precision capacitor to set the free running value has a different value depending on the models.

Someone may have swapped the display section not knowing this or your caps may have shifted values and you cannot sync up the displays until you "kick in the seat of the pants".

Check the horizontal sync signal at the video display and then see if it approximately matches the free running oscillator value;.

WB6IQS, John, Vista, CA

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

On Tue, 2/16/16, pbbob426@... [hp_agilent_equipment] <hp_agilent_equipment@...> wrote:

Subject: [hp_agilent_equipment] 8590E Video Display problem
To: hp_agilent_equipment@...
Date: Tuesday, February 16, 2016, 2:27 PM


?I have an HP 8590E in which there is
no video on initial power up. But consistently, if I shut
the 8590E down anytime after about 2 minutes and turn it
again, the display is perfect - until the next cold
start.?
Anyone have any ideas what
may be causing this?
BobD