I would like to know what happens when a dual power supply op amp misses one of the power rails and what kinds of damage I can expect for op amp.
What prompted this question:
I have a analog PID module from SRS (SIM960). It usually works in a mainframe that supplies the power but because of space constraints I had to supply powers myself (+5V for digital and +/-15V for analog). It worked for a while, but yesterday I discovered that -15V connection had been un-plugged by accident, and the PID module was not behaving correctly. I promptly fixed the connection but now the module seems damaged. At least the input pre-amp section is damaged. The (P gain * error) value does not read correctly, and it seems to be at an almost fixed value, not responding to change in polarity, P gain, or error itself.
The online manual for SIM960 does not show the schematic diagram, and I don't think I can post a copy of the diagram from the paper manual, so the input preamp section looks like instrumentation amplifier followed by some op amps for proportional gain. All the op amps are OPA228/OPA2228.