[volt-nuts] Looking for Advantest (ADCMT) User Manual/Schematics

[Sven Schnelle]

Hi List,

Sven Schnelle <svens at stackframe.org> writes:

> recently i acquired an old Advantest R6581 Multimeter. When i received
> the unit, it didn't show anything on the display. It turned out that
> the backup battery leaked, and some traces on the PCB where
> interrupted. After fixing them,
> it showed the R6581 welcome banner, and after that "RUNNING SELF
> TEST". Now the self test fails with 'Internal Zero error'.
>
> I'm not sure whether that's because it lost all of its calibration
> data, or if that's a real error on the Analog PCB. Does anyone on this
> list have some experience with those units, or a User
> Manual/Schematic?
>
> It would be really sad to have such a nice 8 1/2 digit multimeter in a
> non-working state...

After spending some hours following traces and swapping parts, it turned
out that a OP07D(U107) and a JFET (2N4393, Q201) was the culprit.

Now it looks like i have a fine 8 1/2 Digit Multimeter. I just need to
find a lab which can calibrate it. :-)

Regards

Sven