5005A Signature Analyzer, how to test functionality? (solved)

[WolfmanTech]

Hello, been hanging around reading a while (and watching Dave's videos a while before that), and I figured I'd make my first (of hopefully many) posts starting with this unit of questionable value/use. I have one complete unit and one extra main-board (possibly more, will have to dig out the box it was in!), and I was wondering what it would take to verify proper function. First, I have to let it dry out a bit! Long story short, it's been sitting in a box of misc electronic junk in an unheated/uninsulated shed for over a year and bringing it in from the cold has caused a lot of condensation to form, especially today with all the cooking! Good to meet you all, and I'll see whether it looks safe to turn it on in the next day or three. Happy Thanksgiving!

[MarkL]

The built-in diagnostics should cover just about everything, as described in the service manual section 8-242.  But if you're saying you don't want to use those...

For the signature analysis function you could write some quick code on a microprocessor (arduino, rpi, etc) to clock 1's and 0's into the 5005A.  The result would be displayed according to this algorithm:

  https://www.eevblog.com/forum/testgear/hp-3468a-in-continual-resetinit/msg686142/#msg686142

An even easier approach would be to hook it up to some old but working HP equipment that has signatures listed in the service manual and verify you get those signatures.


I have a 5006A and when I got it none of the front panel buttons worked.  I was sure it was a driver problem.  But it turned out the buttons were so dirty on the inside they no longer made contact.  Every single one of them.  Copious amount of contact cleaner fixed it.  Your 5005A is from the same era.  FYI.

[pelule]

I assume it may easier to use the analyser to measure the generated code of themself.
Just refer to the troubleshooting section and there lock for the diagnostics using a Signature Analyser.

[WolfmanTech]

MarkL- Reading in the two threads on here that mention HP Signature Analyzers had given me the idea this unit didn't have internal diagnostics, but I'll hunt up the manual to find out. As for old HP units to test on, I'll keep an eye out and maybe ask a couple people that might be able to help me there. Thanks!

Pelule- I'll check that out, thanks!

Just to warn everyone, I'm a bit slow on getting things done (due to being depressed and unemployed), but I'll try to post new progress as often as I can!

[PaulAm]

The 5004a has a handy test point on the front panel that supplies a known  signature to verify operation.  I don't know why they left that out on the 5005a/b.

It might be possible to use the 5005a itself and check an internal test point, but generally the instrument under test has to be put into a signature generation mode (usually a jumper somewhere) so it's not doing anything actually useful when  generating known signatures.

Looking in the service manual, they say to use a 5036a microprocessor lab, or an instrument with documented signatures to verify signature analysis.  You can, however, use another signature analyzer to trouble shoot the 5005 

[pelule]

Had some time to search & look more detailed and found the 5005A service manual.
Unfortunately its too big to attach her. So use the link: http://arcarc.xmission.com/Test%20Equipment/HP/HP%205005A.pdf
You may follow the trouble shooting charts. Signature tests for the Kermel are listed from 8-60 (page 177) onwards.
But You may first look to the self-test reslts, if there is an Error Message listed (see table 8-6).

[TAMHAN]

Hello,
I second the suggestion with some old HP gear. Waddle up to someone who has a 4262A or a similar unit, and ask whether he lets you link up to it.

Tam

[WolfmanTech]

Well, I turned it on and it seems to function alright, though when reading its own five-volt port in the rear it reads just under at around 4.8-4.9-ish.
I tried hooking it up to its own internal test points, but as expected that interrupted its own processes and made it reset/flicker.
If I can find some precision things to measure I can test those functions, though I automatically trust it slightly more than my cheap Chinese DMM. XD

PaulAm- Well, I have two fifths of another 5005A thus far!

Pelule- Thanks for the link! It doesn't have any error messages, thankfully.

TAMHAN- I'll see whats available locally, maybe check in with the Maker space!

[pelule]

It doesn't have any error messages, thankfully.

So I reommend to run through the "Perfonce Tests" as decsiped in Chapter 4-1.
Your chinese DMM may good enough to at least compare.

[TAMHAN]

Connecting a meter to its own test points is something I would be very careful about.

Re voltage accuracy: maybe get yourself a cheap voltage reference IC or a sample from somewhere!

[pelule]

Here we are talking of reading the digital signature of a logic system in a 5V logic system at the same GND, so no risk.

[WolfmanTech]

Well, I'd completely forgotten until now, but I do have the HP4935A - Transmission (impairment) Test unit.
Do you folk suppose it has Signatures I could measure? Aha! In the manual for the 4935A there's a section about testing its signatures with the 5004, I can probably sub the 5005A and run the procedure! ...Once I clear the dining table, that is. 

[MarkL]

All the signature analyzer models use the same CRC computation, so you should get the same results.