Agilent 3458A ERRSTR 209, HARDWARE FAILURE

[michaelrusseau]

I have an Agilent 3458A with an ERRSTR 209, HARDWARE FAILURE -- TIMEOUT: UNABLE TO READ A/D: 219 and 114, STSTEM ERROR -- multislope rundown convergence. It is intermittent. I had replaced the A/C board because it had burned up components and now have these error.  Elsewhere on this forum it looks like others suspected the A/D Converter and Inguard Logic A3 board but could it be a bad new A/C board?

[TiN]

Ouch. About 95% chance it's the bad A3 ADC board. You can try to set NPLC 0.001, while in DCV mode.
Meter may read the voltage in such case, which directs to ADC issue once again.
Perhaps my past experience can be helpful for you. 

[Kleinstein]

Besides ADC failure, it could still be a problem with the fiber connection or the µC.

The nasty ADC failure (hybrid ASIC) usually also leads to significant drift in the CAL72 value. So if the meter is still working good enough to get cal72 values, one could check for drift here - with a bad ADC it only take hours to see the drift. Large drift here would be a very strong indication for serious ADC trouble.