Well I got an Agilent 34401A fo free. Condition:
So, I am going to see, if I can figure out what's wrong with it and maybe even fix it.
I haven't really had the time to start any serious debugging yet, but maybe someone here has more experience with fixing DMM-s then me.
The problem description sofar:
"The multimeter doesn't measure voltages under 10V and also might have problems with measuring resistance, current measuring works fine" - I have not had the chance to verify any of this yet.
Self test returns errors:
612 - Ohms 500 nA source failed. This test configures to the 10 V dc range
with the internal 10 M 100:1 divider U102A connected across the input.
The 500 nA ohms current source is connected to produce a nominal 5 V
signal. A 20 ms ADC measurement is performed and the result is
checked against a limit of 5 V ± 1 V.
613 - Ohms 5 uA source failed. This test configures to the 10 V dc range
with the internal 10 M 100:1 divider U102A connected across the input.
The 5 ?A ohms current source is connected. The compliance limit of the
current source is measured. A 20 ms ADC measurement is performed
and the result is checked against a limit of 7.5 V ± 3 V.
I think my first move is to go over the troubleshooting hints in the service manual and see if that brings anything up.
Feel free to give me any hints or ideas