3458A - Pass, then Fail self-test - Error 202 - Is it borked?

[nexus]

Hi all,

I bring before you another 3458A. I've known about this meter for years but just getting around to getting one.

This is an HP unit with option 002.

Apparently, it is not in "Perfect working condition" as described by seller.

First 5-10 minutes of power on, everything seemed normal. Getting small voltage reading on dcv with nothing hooked up. Did self-test within first minutes too, no errors.

Then, after some warm up time (< 20 mins), come back to see "-OVDL." on VDC screen. Strange.

Try switching function to ACV, its showing some readings. Switch to OHM, back to "OVLD".

Run the self test again: 202, "HARDWARE FAILURE -- SLAVE TEST: OVERLOAD"

Hmmmmmmm. Its not the dreaded convergence error I've read about so many times.

Try to hit "RESET", now it boots up with immediate error. Does not show any readings on any settings. Still same SLAVE TEST: OVERLOAD error.

I'm contemplating whether to just stuff it back in a box and open a return case, but I don't want to be too hasty. Am I missing something here? Maybe its a simple issue and not a bad A1/A3 board? As this is my first 3458A I will defer to the volt nuts for a recommendation.

FW version is Rev 8.2.

[TERRA Operative]

I would say it depends on how much you paid. If you got it for market price for a working one, send it back. If you got it at a really good price, try to fix it.

Unless someone else can help find the issue for minimal time and expense.

[Kleinstein]

A first point to check is if the fan is running and the air filter no fully clogged. This could lead to overheating after some time and could be an easy fix. If the price was good, it may with a gample than.

Getting overload with an open input is not necessary an issue. This input is rather high impedance and even an in spec input current (< 20 pA) could drive it all the way to saturation. The error in the self test should however not happen, not cold and defenitely not warmed up.

I would still contract the seller and describe the issue.

[TERRA Operative]

That 202, "HARDWARE FAILURE -- SLAVE TEST: OVERLOAD" error looks like there was an unresolvable overload condition detected in the analogue measurement section during the self test.

That narrows it down to likely the A1 DC Circuitry Board, or the A3 A/D Converter and Inguard Logic Board.

First, check for any other faults by pressing the blue key then the [-] (ERR) key to see if there are any other faults logged and let us know.
Then, check all your power supply voltages are within spec.
After that (pending no other errors) I'd be looking for blown J-FET's or OPAMPS on the A1 board, and checking the A/D converter on the A3 board hasn't failed.

[voltsandjolts]

Send the seller a video. Even if you're keeping it you might get some partial refund.

[nexus]

Send the seller a video. Even if you're keeping it you might get some partial refund.

I contacted seller today, asking for either partial refund or return.

A lot of good suggestions on where to start diagnostics and testing, and I am not shy to try fixing it myself.

We'll see what seller says and go from there!

[nexus]

A first point to check is if the fan is running and the air filter no fully clogged. This could lead to overheating after some time and could be an easy fix. If the price was good, it may with a gample than.

Getting overload with an open input is not necessary an issue. This input is rather high impedance and even an in spec input current (< 20 pA) could drive it all the way to saturation. The error in the self test should however not happen, not cold and defenitely not warmed up.

I would still contract the seller and describe the issue.

Fan is running and filter seems fine, not super dusty.

I will see if it works cold again for a few minutes.

If so, put a short across input with DCV measurement, see if it reading drifts before it hits "-OVLD".

[nexus]

So the 202: "HARDWARE FAILURE -- SLAVE TEST: OVERLOAD" is the only error in the log so far. If ADC is running when cold and passes self test, maybe drifty part(s) on A1 board.

Another interesting thing, when it first threw "-OVLD" on DCV, I switched to "ACV" and it was still doing readings. I switched do DCI, back to "-OVLD" and back to DCV "-OVLD". So maybe that points to A1 DC board more than A3.

If I keep it, I will definitely share investigation here for troubleshooting!

That 202, "HARDWARE FAILURE -- SLAVE TEST: OVERLOAD" error looks like there was an unresolvable overload condition detected in the analogue measurement section during the self test.

That narrows it down to likely the A1 DC Circuitry Board, or the A3 A/D Converter and Inguard Logic Board.

First, check for any other faults by pressing the blue key then the [-] (ERR) key to see if there are any other faults logged and let us know.
Then, check all your power supply voltages are within spec.
After that (pending no other errors) I'd be looking for blown J-FET's or OPAMPS on the A1 board, and checking the A/D converter on the A3 board hasn't failed.