Hi List, 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... Regards Sven

Hi List, Sven Schnelle <svens@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