Continuing my repair of an HP 6115A power supply, I think I've managed to bolox up the analog meter in this thing. It responds to changes, but it seems to have a non-linear response now, and so if I calibrate it for the full-scale value of 100V, then when I set the Power Supply to 20V, the meter is reading high (about 30V). It was off when I got it, but something I did during the repair made it much worse (possibly the time I powered things on forgetting to plug back in the control board first, leading to the meter seeing an overvoltage condition).
I've looked at the circuitry surrounding the meter, and it just boils down to a resistor in series with it, so I don't see that being the source of the problem. To confirm, I removed the meter from the PS and connected it to a programmable current source. I was able to confirm the non-linear behavior that I see when connected to the PS.
Is it possible to repair this?