I bought a Datron 1065A and it seemed to work the first few minutes. However, then I heard a sort of ticking noise, similar to the noise you hear when a heater is turned off and it is cooling down fast. After that the meter was always showing "over limit" no matter what I did on any range, and errors 5, 6 and 7 on the self test. I was lucky to get the service and calibration manual for 1065/1065A with the meter.
It turns out the tantalum capacitor C14 near the integration circuit was toast, along with a nearby resistor that is connected between the capacitor and ground. It was easy to find the error after checking the test points oscilloscope waveforms shown near the integration circuit. I changed it to a multilayer ceramic of the same value, and now it works again.
But my real question is: I did not find the 1065A service manual online. Should I scan mine and upload it, or is it already available somewhere, despite my failed attempt to find it online?
Best regards,
Torquil