HP 34401A malfunction

[jmoreland79]

I have an HP 34401A that has an issue measuring AC voltage.  With voltage applied, the display freezes and does not display the actual voltage.  Other measurements (DCV, resistance, continuity, etc.) seem to be read ok.

I figure something is fried inside, but I'm wondering if it's something that's easily repairable or I should just send it out for repair.  The unit was last calibrated in February 2015.

[jitter]

Have you tried running the self tests?
If not, press the shift-button and power it on, release the shift-button after a few seconds and the self tests should start.
I wonder if that comes up with an errorr code.

[jmoreland79]

Thanks, I had not run those tests but I did and everything passed.

Hmm, not sure what's going on with it.

[bitseeker]

Does using the rear inputs work normally? Does the problem occur in manual ranging mode? Does it happen at all ranges while in manual mode?

[sarepairman2]

this thread title = nightmare situation

[jmoreland79]

The rear inputs give the same results.

However, it seems the issue only appears when trying to take a high frequency (165V 110kHz).  Measuring mains voltages (120-277, 60 HZ) seems to be fine.

[bitseeker]

That's odd. Should be OK up to 300kHz. 

[ManateeMafia]

If you have a signal generator, you can test if it is frequency dependent if you haven't tried it already.