Considering purchasing a Logic Analyzer

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I don't think this one contains that kind of data Stj. I read on EEVBlog how I guy had to replace his because it wasn't retaining the calibration data. He gave a link to Mouser I think, where they had replacements and said just unsolder the old, solder the new one in, recalibrate and away you go.

20+ years?! That's insane. This oscilloscope module is around 20 years old. If it's working, I'll probably just keep it I guess. No sense in replacing something that isn't broke. Got ten 10nF 100V 10% MLCC SMD caps coming from Mouser. I was surprised how cheap shipping was compared to Digikey. It was nice.

[stj]

Re: Considering purchasing a Logic Analyzer

i'v seen those zero-power rams go 20years+
the data in it may be something you cant regenerate that was created with a test-rig.
it may also contain a MAC or serial number for the board.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I think you will be alright with the higher voltage. I guess if you can not get any schematics on this thing Then you might as well start replacing things. First I would run all the diagnostics on the logic analyzer with the O-scope board out, then start replacing things on the O- scope and see if you get the trigger back. Some of the circuity will most likely be to fast for you to look at with your other scope. You are kind of flying blind. You have to figure that it worked at one time. There is a 95 % chance it is a component that is bad. The only problem with troubleshooting this way is if you have parts dependent on each other, so that if you replace one part the other part will take the new one out and visa-versa.

I still haven't tried HP yet, still can't find an e-mail address. How do you guys know so much about all this stuff? It just blows my mind! So, run the diags on the logic analyzer first, with no o-scope module, then plug the o-scope module in, run the diags on the o-scope module, record the results, replace the caps (when they come in the mail), run the diags again. If it still fails, replace the IC, run the diag again, right?

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

the battery-backed ram may still be good, you need to back it up because it's probably got calibration data in it.

Okay. If I replaced it, once I got everything working good, I was going to try and recalibrate everything. You're right, supposedly it holds the calibration data. I just figured as old as it was, it was probably bad.

[stj]

Re: Considering purchasing a Logic Analyzer

the battery-backed ram may still be good, you need to back it up because it's probably got calibration data in it.

[keeney123]

Re: Considering purchasing a Logic Analyzer

I think you will be alright with the higher voltage. I guess if you can not get any schematics on this thing Then you might as well start replacing things. First I would run all the diagnostics on the logic analyzer with the O-scope board out, then start replacing things on the O- scope and see if you get the trigger back. Some of the circuity will most likely be to fast for you to look at with your other scope. You are kind of flying blind. You have to figure that it worked at one time. There is a 95 % chance it is a component that is bad. The only problem with troubleshooting this way is if you have parts dependent on each other, so that if you replace one part the other part will take the new one out and visa-versa.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

With capacitors, I can always go over, with the voltage, right? I have evidence to believe it's a 10nF. I can't prove it but someone who has them found two others that appear to be identical on the same circuit. I pulled those two others and measured them on my board and they were both 10nF. I figured if there's four caps in the same circuit that appear to be the same height / width / length, if I have no other ways to tell, it'd be okay with assuming at this point that they are the same caps.

The package seems to be a 0805. I found some 0805 10nF 100V MLCC SMD caps at Mouser. If the real caps are only like 16v, would 100V do any damage? Or could I safely use them? I thought the voltage was just the maximum amount of voltage the cap could handle...

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

http://www.woodmann.com/crackz/Flexlm.htm

So, I can use that to generate license keys, if my Logic Analyzer uses the FLEXlm stuff?

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

license servers will be for FLEXLM, seen SGI using that crap.

btw, what's this part in red, a battery-backed ram?

Wow, you are good! My crappy photo and you could tell! It probably needs replacing. It's:
H990A9922
M48Z18-100PCI
ZEROPOWER RAM
Lithium Battery
Malaysia. Written sideways, there's also a W1749X on there. I planned on replacing it once I got the triggering fixed (or at least the IC and the two 10nF SMD caps).

[stj]

Re: Considering purchasing a Logic Analyzer

http://www.woodmann.com/crackz/Flexlm.htm

[stj]

Re: Considering purchasing a Logic Analyzer

license servers will be for FLEXLM, seen SGI using that crap.

btw, what's this part in red, a battery-backed ram?

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I dunno Stj. I guess they could be lying, but that's a long time to keep the stuff around. The guy I talked to seemed to really want to try and help people. For example, the OS reinstallation discs were gone. He told me whenever they tried talking to HP, they had a heck of a time getting them to help, after they purchased everything. I found the ISOs for the reinstallation discs and gave them to the KeySight guy and he actually uploaded them on the KeySight FTP server for all to download, after verifying they were legit and everything. I'd think if he was lying, he wouldn't of cared about stuff like that, you know?

The servers were special. Not modern day. They had a mainframe running some software that was used to generate licenses for one thing or another. I don't know what the licenses were for, but if someone hasn't required a license in 5 years or so, I could see the company making a decision to scrape the special servers, rather than paying to keep them running in case one or two users _might_ need a license in the future. One of those do the pro's outway the con's?

I did tell him how I thought in the future, if they were going to destroy stuff like that, maybe they could release it open source before doing so. I could try e-mailing KeySight instead of talking to an employee directly on the site and HP as well, just to see if I get the same answers or not. I guess that would help show us if anyone's being deceptive. I still can't find an e-mail address for HP. I really hope I won't have to call them on the telephone.

[stj]

Re: Considering purchasing a Logic Analyzer

i suspect they are lying and just want you to buy a new model rather than repairnig the old one.
typical company attitude these days.

they wont have lost the schems or software because they make up part of the patent and would be needed in any legal case against a cloner

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

I would then go back and contact HP try and talk to a tech in the service repair department and see if he will locate the schematic for this board. The unit is not that old they still should have them. He is says he does not then ask of a similar schematic so you can figure out the triggering circuit. There o-scope circuits should be similar as they are performing the same function. They have been making O-scopes since at least the 1950's.

Thanks Keeney, I'll try that. I have a feeling though, since they sold everything for these logic analyzers and that oscilloscope module to KeySight, they might of just got rid of it. KeySight now owns the rights. I want to say it was 2010 when the KeySight employee they they did away with all the stuff. Something about how it costed money to run the HPUX servers or something and to keep all that stuff around. He said because it's over 20 years old, it's now considered obsolete and they did away with everything.

How should I contact HP? I think I'd probably have more luck with the business end of HP, rather than the consumer end. Maybe I can find an e-mail address on their site.

[keeney123]

Re: Considering purchasing a Logic Analyzer

I would then go back and contact HP try and talk to a tech in the service repair department and see if he will locate the schematic for this board. The unit is not that old they still should have them. He is says he does not then ask of a similar schematic so you can figure out the triggering circuit. There o-scope circuits should be similar as they are performing the same function. They have been making O-scopes since at least the 1950's.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

Okay Stj. I just don't think the schematics were ever released to the public. I contacted a person who was working on these modules. He said he believed HP has these things called CLIPs (Component Level Information Packages) but he's never found one on the net or anything. I've got the service manuals for both the oscilloscope module and the logic analyzer but they just seem to tell you how to calibrate the equipment and gives part numbers for replacement parts. You know, real simple stuff for field workers or something. If the board fails the test, try this. If that doesn't work, replace the board with this part number. If the oscilloscope probe is bad, replace it with this part number, etc.

Anyway, here's the pictures I promised. Sorry that they're so dark. I had all the lights on in the house but it didn't do much good. DSC01507 shows a zoomed up picture where the two missing caps are. One has a missing pad but I think I can solder to the little bit of pad that's missing or solder to the via that it goes too. The circuitry in DSC01507 is on the back side of the board, same place where the AMCC chip is. Just on the back instead of the front. The AMCC chip had a heatsink that I removed. I hope these help.

[stj]

Re: Considering purchasing a Logic Analyzer

check monthly, they are on a mission to archive ALL old stuff!!!

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

http://bitsavers.informatik.uni-stuttgart.de/

Thank you for the link Stj. However, I can't seem to find any information there on the Agilent / HP / KeySight 16702B Logic Analyzer or the HP 16534A Oscilloscope module.

[Spork Schivago]

Re: Considering purchasing a Logic Analyzer

Did you ask through the support site or the blog site for help? In other words did you ask the company directly or just the people on the help site? Seems like to test this out you will need an accurate power supply and a signal generator. So the scope is a plug in module and the problem is on that module? The chip you are concerned with has a phase lock loop and works on ECL and TTL logic. When we use to troubleshoot something like this we used an extender board. Just a board that brought the back plane out so we could use a scope on it. . It would plug into the connector and the O-scope board would plug into it. This way it would be out in front of the chassis. The Logic Analyzer should also have a trigger circuit which may allow you to monitor what information is transpiring on the chip you are concern with. Seems like if you run through either the test mode or calibration mode the machine will tell you where it failed. I might be a good idea to post a close up of the o-scope module so we can see what you are working with. I would first run the test mode out of the whole machine to see where it failed and to verify the other parts are good.

Thank you Keeney123. I asked on the blog but a KeySight employee answered me. He was the one that worked on the development of the credit card demo board or whatever it's called for this logic analyzer. It's just basically a development board for it.

The test was ran and it showed triggering failed. When I did some research on this, I found that little riser board next to the IC seems to also be part of the triggering circuitry. Right now, without those caps, the triggering will still fail. I do have an old signal generator. It can only do up to 5MHz though. I also have another oscilloscope (100MHz bandwidth). I'm thinking if I could find the proper 10nF caps (the right voltage ones), I could just solder them where the old ones got ripped off / blew up / whatever and try the module, to see if it fixes the triggering. If not, then I'll try replacing the IC to see if that fixes it. It's just now a matter of trying to figure out what 10nF SMD caps to use. I'll post some pictures in a little bit here. Thank you!

[keeney123]

Re: Considering purchasing a Logic Analyzer

I did ask for help on KeySight's site, they're the ones who told me the schematics have long since been destroyed, along with most of the other information (like source code to the HPUX OS, etc). However, I did find a service manual on the oscilloscope module, just no schematics. I also found a datasheet on the IC but it's kind of lacking. The oscilloscope module is HP 16534A. The IC is an AMCC Q20025-0080B. This is the closest thing I could find for a datasheet for that IC...



Service manual for the 16534A is here:


Here's another link for the same document:
https://cdn.badcaps-static.com/pdfs/...dcd515e29b.pdf

The logic analyzer that the oscilloscope module goes into is an HP 16702B
Thanks for the help!

Did you ask through the support site or the blog site for help? In other words did you ask the company directly or just the people on the help site? Seems like to test this out you will need an accurate power supply and a signal generator. So the scope is a plug in module and the problem is on that module? The chip you are concerned with has a phase lock loop and works on ECL and TTL logic. When we use to troubleshoot something like this we used an extender board. Just a board that brought the back plane out so we could use a scope on it. . It would plug into the connector and the O-scope board would plug into it. This way it would be out in front of the chassis. The Logic Analyzer should also have a trigger circuit which may allow you to monitor what information is transpiring on the chip you are concern with. Seems like if you run through either the test mode or calibration mode the machine will tell you where it failed. I might be a good idea to post a close up of the o-scope module so we can see what you are working with. I would first run the test mode out of the whole machine to see where it failed and to verify the other parts are good.