Re: What happened to HP/Agilent detailed circuit schematics
I hear R&S makes some nice gear, I don't have any.? Pretty much unrepairable.
I was given a very nice R&S transceiver that pretty much worked but has some problems.? Unrepairable, even with module swap, due to recalibration being necessary.? And special software is required which is not released outside the company.? The cost to get that done far exceeds the value of the radio, if R&S would even perform the work for an individual, which they won't.? What a turn-off.
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On 8/27/2024 4:54 AM, alwyn.seeds1 via groups.io wrote: Dear All,
One of the issues has been change of customer requirements. Back in the HP Days, the US and other military customers did component level equipment repair; they therefore required complete service documentation, the structure of which was defined down to the typefaces to be used. Those customers met the very considerable cost of creating this documentation. Post Cold-War, the military customers changed their repair policy, the proportion of business that was military reduced and the manufacturers responded accordingly.
We are very fortunate that both HP and Tektronix made much of the documentation available to all customers. Other manufacturers, such as Rohde and Schwarz, did not.
Regards,
Alwyn
_____________________________________________________
Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.
SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom.
_____________________________________________________
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Re: What happened to HP/Agilent detailed circuit schematics
I don't agree that programming a custom chip is difficult.? Chip programmers are cheap and plentiful on the market and common with hobbyists.
What may be uneconomical for a manufacturer might be very economical in a repair situation.
Take two examples:
A manufacturer considers it uneconomical to repair a PCB, but they have no stock of replacement boards.? This forces the customer to purchase an entirely new instrument instead of repairing what might be a simple fault.? This might be a win for the manufacturer but the customer sees it as a costly loss.
An aerospace or military customer has approved test procedures which involve very specific pieces of test equipment which are no longer supported.? Changing the procedures would be enormously expensive due to the approval process, far in excess of the cost of new equipment.
The manufacturing processes themselves may be easier than they seem.? For example replacing a BGA part on a modern PCB seems to be a daunting maybe impossible task but with the right equipment and skills even sidewalk vendors in some Chinese cities can do it successfully right there in front of you in a few minutes.
Sure, I've repaired many pieces of equipment without any service info but it can be hit or miss.? Most frequently, and for most people, the difference between repairable and not is that of documentation.
Peter
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On 8/26/2024 11:40 PM, Chuck Harris via groups.io wrote: Sadly, I didn't think you would understand...
I inferred your desire to share in proprietary manufacturing
processes from what you were asking.
Programming a custom chip is a part of the manufacturing process
(just like forging a tungsten filament). It requires specialized
equipment, and specialized knowledge that most are incapable of
understanding even if it is spoon fed to them.
We think nothing of replacing the whole light bulb, when the
filament burns out (although that hasn't always been the case)...
Why is it so hard to understand that like a light bulb, a modern
circuit board can also be uneconomical to repair?
-Chuck Harris
On Mon, 26 Aug 2024 14:46:49 -0700 "Frank Mashockie"
<fmashockie@...> wrote:
Nice try smart ass.? Where did I say share their manufacturing
process?
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Re: HP8566B - Making sense of the figures
That's very noble of you, Ozan. And if it's of any reassurance, leaving everything I own to animal charities has been my plan all along and I made a Will out to that effect many years ago. Now a working 8566B will become a part of that estate and add some useful value to it!
One final time: THANK YOU!
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Re: What happened to HP/Agilent detailed circuit schematics
Dear All,
One of the issues has been change of customer requirements. Back in the HP Days, the US and other military customers did component level equipment repair; they therefore required complete service documentation, the structure of which was defined down to the typefaces to be used. Those customers met the very considerable cost of creating this documentation. Post Cold-War, the military customers changed their repair policy, the proportion of business that was military reduced and the manufacturers responded accordingly.
We are very fortunate that both HP and Tektronix made much of the documentation available to all customers. Other manufacturers, such as Rohde and Schwarz, did not.
Regards,
Alwyn
_____________________________________________________
Alwyn Seeds, Director
SynOptika Ltd.,
114 Beaufort Street,
London,
SW3 6BU,
England.
SynOptika Ltd., Registered in England and Wales: No. 04606737
Registered Office: 114 Beaufort Street, London, SW3 6BU, United Kingdom. _____________________________________________________
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Re: What happened to HP/Agilent detailed circuit schematics
While the commercial reasons for poor repair documentation are easy to appreciate, this is an example of where the most profitable route is not best for society as a whole. There are many such examples in other fields and it's why we empower government to legislate and enforce more socially-acceptable behaviour.
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For example, insider trading, competition law, and even very specific examples such as laws in some countries to prevent car manufacturers from limiting access to service information to their own agents. Users then have a meaningful right to choose their mechanic (including themselves). Yes, there are safety and cost implications and these are considered when these laws are made. There are also safety and cost implications of making a product that is not dangerous. Manufacturers are still expected to abide by them.
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So yes, it's a problem affecting profitability for manufacturers. But profitability is not an absolute right (even in America). In a well-governed society, manufacturers have to expect to incur some costs that are of wider benefit to society. Otherwise, they are not respecting that society and cannot be considered a productive member of it just like a sociopath or criminal. It's not a choice. If those standards mean that the product is not economically viable, then so be it.
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Re: What happened to HP/Agilent detailed circuit schematics
Nik, what you describe is broadly speaking correct for Keysight too. They too have people who estimate the need for new and rebuilt assemblies for the period after product obsolescence. If an instrument cosnists of a giant board with everything expensive on it, that board will be repaired at the factory or at the CM if it's worth doing. Keep in mind though that Keysight has thousands of products in support, which is different from Apple.
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I can't say anything about the level of repair difficulty when comparing Apple and Keysight products. Apple products are made in extremely high volumes. Even the best selling Keysight items are "cottage industry" in comparison. Another difference is the end user. In Apple's case it's the general population, which is very different from selling to manufacturers (like Apple). Another big difference is the life cycle. A seven year old Apple phone is considered past it's expected life span.
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These days, parts and assembliess from Keysight become unavailable pretty soon after the required support period ends. For example, recently I was not able to get a LCD panel for an instrument they stopped making less than six years ago. Regarding CLIPS, they do of course exist, but many aren't formatted for presentation outside of the company. There is a lot of cost cutting and it will only get worse in that regard.
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Vladan
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Re: What happened to HP/Agilent detailed circuit schematics
Im not sure thats quite the whole story Vladan, or at least it wasnt for me in the early 2000's when i worked for Applecare Engineering. You dont simply create all the spare assemblies you think you will need for the projected lifetime of a range of equipment. You create the equipment and calculated (based on past product data) how many spares/assemblies you will need, and when someone needs a spare you send one out and the old one is returned. The returned one are not simply thrown out, and you dont create as many as you think you will need but a percentage of how many is required.
If a returned part is serviceable, that is it isnt burnt or damaged in some way as to make it expensive/unreliable/unusable to repair, that part would be component level repaired and put back into service stock after testing. Third party component level repair contractors were doing the repairs for different regions, for Apple at least. These repairs need to follow procedures and process specified by manufacturer (within Applecare Engineering for Apple products from my experience) so the contractors definitely have repair procedures and schematics (and sign strict NDA's to be able to get them) . We (me as an Applecare engineer in my case) would go certify the contractor when they take on these contracts and when they take on new products, to ensure the repair line and all procedures/processes were followed to meet Apple's specifications. I know other computer companies and equipment manufacturers also followed the same procedures.
This wasnt? some isolated Apple magic management practice to get maximum efficiency while meeting consumer protection laws from various regions, this was done by most other large tech manufacturers also to the best of my knowledge. When the product support requirements ended, any remaining stock of spares, if there were any, were sold off to recoup any money and space. Components for component level repairs were the only thing that were ordered as needed once the production lines closed on a product, and hopefully your calculations were correct on the number of spare assemblies that were created to meet service requirements, and they usually were from memory.
I think the existence of these CLIP files after the 80's reinforces the idea that component level repair procedures were still created (probably to this day), just not released like they were prior to the 90's.
My 2cents worth.
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Re: What happened to HP/Agilent detailed circuit schematics
When the supply chain fails as happened with Covid, it could even become a national security issue when companies are unable rather than unwilling to make timely repairs¡and where new equipment might not be readily available ignoring e-waste
and financial aspects.
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Re: What happened to HP/Agilent detailed circuit schematics
Frank,
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I will tell you something interesting. At Keysight, they still have a few people who repair broken in house equipment (e.g. for the R&D lab). However, if they have to dig deeper than described in the service manual, they will just swap an entire assembly. If the assembly is no longer available, they will reply that they can't fix the instrument, it's too old.
Manufacturing has become incredibly efficient at large companies, it just isn't economically justifiable to spend time on complex repairs. Even way back in the good old days when service manuals had everything in them, production line techs had a time limit to find a problem or else scrap an assembly.
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Vladan
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On Mon, Aug 26, 2024 at 08:47 PM, Frank Mashockie wrote:
Vladan,
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I really appreciate your input as you do have the advantage of all 3 vantage points.? I am not a designer.? I am a consumer and a professional repair engineer.? And I think you take my comment "for the sharing of information and community knowledge" lightly and I think that is a mistake.? I guess there a those who believe in an open source method of sharing information and those that do not.? I think the former has greater benefits to society.
?
This is something that affects all of us negatively whether you want to believe it or not.? Making things more difficult to repair (i.e. not providing service manuals, schematics, etc.) has negative consequences both directly and indirectly.? It hinders growth for those who need the equipment.? It hurts small businesses and allows bigger ones to continue to flourish.? The amount of money I save my company by providing them in-house services and drastically reducing their reliance on manufacturers is significant.? What is absurd to me is that the manufacturers who provide our equipment have told me directly (real quote) "we do not support customer repair of our instruments".? To add to that absurdity we all consider ourselves scientists.? We should be supporting one another to do good science, not hinder it.??
?
And then of course there is the toll on the environment created by all the waste repair preventation strategies bring.? The manufacturers don't deserve all the blame.? Consumers share the blame, too.? So its a problem that has many implications.? I think it is our duty as engineers to fix it.
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-Frank
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Re: What happened to HP/Agilent detailed circuit schematics
Yes, times have changed and that is what the OP lamented. Until around 1990, it was still economical to have an in-house repair department that could find a bad IC or transistor. Almost everyone shopped first at HP and Tek because the equipment was very well made and serviceable. The lack of documentation is probably the main reason I never bought any R&S or Anritsu equipment even though both made some nice products over the years.
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I suspect that if there is a competitive advantage to publishing detailed documentation while charging the required amount to stay in business, someone would do that. Yet, nobody is stepping forward. Also, keep in mind that the number of skilled repair technicians is diminishing. Production lines are mostly using operators to make adjustments via software. There aren't many people left who are willing/able to find an open 5 mil trace somewhere inside a 16 layer circuit board with FPGAs. Tinkering with modern cars and electronics isn't much fun any more. I have a mix of old and new equipment. I like them both, but for very different reasons.
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Vladan
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Re: What happened to HP/Agilent detailed circuit schematics
Chuck,
Fair enough.? I get your point.? I think you could have used a better example though.? I understand the difficulties in passing legislation.? I already stated that I don't think legislation is the best way.??
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The difference between your example and mine is that the average consumer does not have the tools to manufacturer lightbulb filaments.? But they can easily grab the tools to repair their own electronics.? Especially if the manufacturers provided them the resources like they used to.
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Also, IMO the main factor that decides whether or not a repair is economically viable is time.? And what sets aside modern equipment from older ones is that service resources aren't made available anymore.? Which makes repair longer.? I have no problem getting modern equipment repaired as fast as older equipment when the schematics/service tools are available.? In fact, sometimes the modern stuff is quicker.? SMD work is faster than thru hole IMO.??
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-Frank
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Re: What happened to HP/Agilent detailed circuit schematics
Vladan,
?
I really appreciate your input as you do have the advantage of all 3 vantage points.? I am not a designer.? I am a consumer and a professional repair engineer.? And I think you take my comment "for the sharing of information and community knowledge" lightly and I think that is a mistake.? I guess there a those who believe in an open source method of sharing information and those that do not.? I think the former has greater benefits to society.
?
This is something that affects all of us negatively whether you want to believe it or not.? Making things more difficult to repair (i.e. not providing service manuals, schematics, etc.) has negative consequences both directly and indirectly.? It hinders growth for those who need the equipment.? It hurts small businesses and allows bigger ones to continue to flourish.? The amount of money I save my company by providing them in-house services and drastically reducing their reliance on manufacturers is significant.? What is absurd to me is that the manufacturers who provide our equipment have told me directly (real quote) "we do not support customer repair of our instruments".? To add to that absurdity we all consider ourselves scientists.? We should be supporting one another to do good science, not hinder it.??
?
And then of course there is the toll on the environment created by all the waste repair preventation strategies bring.? The manufacturers don't deserve all the blame.? Consumers share the blame, too.? So its a problem that has many implications.? I think it is our duty as engineers to fix it.
?
-Frank
?
?
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Re: What happened to HP/Agilent detailed circuit schematics
Why am I here? Possibly to teach guys like you that modern equipment isn't always economical for guys like you and me to repair. Companies providing schematics wouldn't change that fact one iota. -Chuck Harris On Mon, 26 Aug 2024 14:55:34 -0700 "Frank Mashockie" <fmashockie@...> wrote: This entire group is only possible because HP/Agilent for a time used
to provide schematics.? They still provide service manuals as far as
I am aware.? That is all proponents of right to repair are asking
for.? To prevent the manufacturers from monopolizing the repair
market.? And to allow consumers to repair the things they bought
themselves however they would like.? If you don't agree with that,
then why are you in this group Chuck?
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Re: What happened to HP/Agilent detailed circuit schematics
Sadly, I didn't think you would understand... I inferred your desire to share in proprietary manufacturing processes from what you were asking. Programming a custom chip is a part of the manufacturing process (just like forging a tungsten filament). It requires specialized equipment, and specialized knowledge that most are incapable of understanding even if it is spoon fed to them. We think nothing of replacing the whole light bulb, when the filament burns out (although that hasn't always been the case)... Why is it so hard to understand that like a light bulb, a modern circuit board can also be uneconomical to repair? -Chuck Harris On Mon, 26 Aug 2024 14:46:49 -0700 "Frank Mashockie" <fmashockie@...> wrote: Nice try smart ass.? Where did I say share their manufacturing
process?
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Re: What happened to HP/Agilent detailed circuit schematics
I am a hobbyist and also a professional in engineering who has for decades made purchasing decisions.? In my career I have leaned toward buying equipment that is supportable.? Yes now that is getting very rare but in the past it meant a lot of business went to HP/Agilent due to their extensive documentation.? While I was not at huge companies that business still added up to millions of dollars and that documentation was often what tipped the scales.? The HP salespeople I talked to told me I was certainly not the only one who felt that way.
The worst these days is equipment which requires proprietary software to even swap a module, and that software is factory-only with some manufacturers.? When support ends you throw the equipment out as it is worthless even as a parts mule.
Peter
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On 8/26/2024 10:10 PM, pianovt via groups.io wrote: On Mon, Aug 26, 2024 at 01:00 PM, Frank Mashockie wrote:
As consumers, repairs, or designers we shouldn't allow manufacturers to
continue these repair prevention strategies that ultimately stifle the
sharing of information and community knowledge.
Frannk,
I can speak about this topic from all the vantage points you mentioned. I am a consumer, I do like to repair some of my equipment (but not all), I have designed test equipment at HP, and I own a manufacturing business.
I can assure you that engineers at HP/Agilent/Keysight never spent any time pondering "sharing of information and community knowledge". That just isn't anything that ever crossed our minds. I/we did spend a lot of time thinking about how to make troubleshooting efficient for a service technician. Increasingly, the best solution is to tell the technician how to identify the defective assembly and just swap it because repair requires special tools or knowledge that I could not reasonably expect a technician to have. Most HP/Agilent/Keysight products contain at least one, but often several novel or clever ideas in them. Remember that Keysight at any one time has thousands of supported products.
Nowadays, assembly level repair is in most cases the most efficient repair method. Troubleshooting down to component level is prohibitively expensive. Keep in mind that HP/Agilent/Keysight is using a different business model than, say, Heathkit (which went out of business). Companies that buy equipment want reliable products with minimal down-time. The engineers working at those companies may or may not be enhusiastic hobbyists when they go home, but they are not the ones paying for the equipment.
Finally, consider the implications of Keysight publishing the schematics for a LCD display or power supply which is purchased form an outside vendor. It's hard enough to find a good supplier without asking them to release documentation for the "sharing of information and community knowledge".
Vladan
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Re: What happened to HP/Agilent detailed circuit schematics
On Mon, Aug 26, 2024 at 01:00 PM, Frank Mashockie wrote:
As consumers, repairs, or designers we shouldn't allow manufacturers to continue these repair prevention strategies that ultimately stifle the sharing of information and community knowledge.
Frannk,
?
I can speak about this topic from all the vantage points you mentioned. I am a consumer, I do like to repair some of my equipment (but not all), I have designed test equipment at HP, and I own a manufacturing business.
?
I can assure you that engineers at HP/Agilent/Keysight never spent any time pondering "sharing of information and community knowledge". That just isn't anything that ever crossed our minds. I/we did spend a lot of time thinking about how to make troubleshooting efficient for a service technician. Increasingly, the best solution is to tell the technician how to identify the defective assembly and just swap it because repair requires special tools or knowledge that I could not reasonably expect a technician to have. Most HP/Agilent/Keysight products contain at least one, but often several novel or clever ideas in them. Remember that Keysight at any one time has thousands of supported products.
?
Nowadays, assembly level repair is in most cases the most efficient repair method. Troubleshooting down to component level is prohibitively expensive. Keep in mind that HP/Agilent/Keysight is using a different business model than, say, Heathkit (which went out of business). Companies that buy equipment want reliable products with minimal down-time. The engineers working at those companies may or may not be enhusiastic hobbyists when they go home, but they are not the ones paying for the equipment.
?
Finally, consider the implications of Keysight publishing the schematics for a LCD display or power supply which is purchased form an outside vendor. It's hard enough to find a good supplier without asking them to release documentation for the "sharing of information and community knowledge".
?
Vladan
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HP 141T Power Supply Help Needed
Good Evening to the group!? ?First post but I've been reading a ton for a few weeks now.? ?
(I thought I posted this but I don't see it, so I'm reposting.. please delete if i did something dumb)?
I've got a 141T with a 1615a prefix.? It's power supply was a mess when I got it,?
almost every fuse was blown and most supply's were measuring high.? ?I replaced the?
V1 regulator tube with a string of diodes and began debugging more.? It seems like most?
of the drivers and differential amps were having _some_ problem.? ?I've measured most of?
the transistors out of circuit and replaced with parts as recommended by other posts.? ?
At this point, I've got improved but still not great results. I've checked passives as best I can and I have measured
around the transistors a bit.? Obviously trying not to blow anything up with the tight confines of the A2 board.? ?
?
With the supply wires on the left removed to the rest of the unit, general voltages are as follows:?
* +102v which seems decent
* about -82v instead of -100v
* 300v instead of 248v, if it were tubes I'd almost expect this with an unloaded supply but I don't think I do expect it here.?
* -1.5v instead of -12.6v.? ?
Acknowledging the dependencies between supplies, I'm starting at the -100v supply since +100 looks "ok" (for now at least).??
In the affected supplies, I "believe" all transistors and resistors are good but some of the zeners measure a little funky (maybe).??
Looking for guidance or advice to break down the problem a bit and work through it.? ? ?
TIA, Bill - WW1H?
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Re: HP8566B - Making sense of the figures
Congratulations Jinxie, your hard work and determination paid off. Your dual transistor construction looked great and will be an inspiration for others. I also enjoyed the challenge, no need for any gift. If you feel you have to do something you can make a small donation to a local animal shelter or charity.?
Ozan
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On Mon, Aug 26, 2024 at 10:23 AM, Jinxie wrote:
Indeed, and I've just done it. No sign of any YTO warning and the FM stations are back where they should be, too. I think we can call that a successful outcome, Ozan!
I'm extremely grateful for your knowledge and persistence in getting this thing back into fully working order again. No way could I have done it without you, that much at least is certain. Do you have a Paypal account? If so, PM me your particulars and I'll send you a 'drink' as we say as a gesture of my sincere gratitude for your guidance and expertise. Well done!
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Re: HP8566B - Making sense of the figures
Thank you for the nice words Barry. I can assure you no computers were harmed during the debug :) I like the puzzle of hunting for the fault, especially on older HP and Tek equipment where there is excellent schematics and documentation. However, as I repaired more equipment my bench and garage space started filling up. This is best of both worlds, I still enjoy the debug and I don't have to think about where to store the equipment afterwards.
Ozan
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On Mon, Aug 26, 2024 at 10:42 AM, n4buq wrote:
I have trouble convincing myself that Ozan isn't an advanced computer sent here from the 23rd century.? He has an amazing wealth of knowledge and so willing to help with all sorts of trouble-shooting.? I don't know how he does it but I'm very glad he does.
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Congratulations on the repair!
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Barry - N4BUQ
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Indeed, and I've just done it. No sign of any YTO warning and the FM stations are back where they should be, too. I think we can call that a successful outcome, Ozan!
I'm extremely grateful for your knowledge and persistence in getting this thing back into fully working order again. No way could I have done it without you, that much at least is certain. Do you have a Paypal account? If so, PM me your particulars and I'll send you a 'drink' as we say as a gesture of my sincere gratitude for your guidance and expertise. Well done!
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Re: HP8566B - Making sense of the figures
@jmr
Thanks for the suggestion; I guess now - or nowish - would be optimal. If I can find the time tomorrow I shall do so (but it will definitely be under a new subject title as this thread has definitely got waaayyyy too long!!)
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Jinxie
Nik Milosevic
Frank Mashockie