@omegaman,
I hope you're still checking in from time to time. I picked up non-working R-82.
This is my latest observation. These selections were made in secession one after the other after each record had been returned and magazine returned to home position. It seems to show a warmup of circuitry.
Selection 101 picks up Slot 9 rather than Slot 1, next time Slot 6, then 2, & 2 and then 1, 1, 1. I then selected 102-106 and it picked them correctly. Then I selected a B side, and I heard a click (B side solenoid) and the display stopped on the correct number, but the magazine continued to spin without end and the data LED had stopped flickering and was out. I cycled the power at the Scan Control Console and when it came to rest, I reset the Memory Unit. The data LED is lit, doing its flickering but now misses every point selected and will no longer pick up any records. Sounds like something was not only warming up but failing and the Mech. Control isn't receiving any signals. I checked all the transistors and diodes in the Memory Unit. Maybe a weak cap or resistor changed value while being loaded? I would just replace all six of the fixed capacitors, but I imagine four of them would have an effect on the trimmer cap circuit.
I see you set the frequency of the trimmer cap at 48 KHz on both the Memory Unit and Selector Logic unit. On the Memory Unit are you measuring the frequency right at chip Z704 Pin #7, Clock Send and (chassis as ground) also at Clock Send Pin#25 at Selector Logic chip Z501?
Thanks for any help that can be offered. These boards were worked on by someone who offered to help the previous owner. They were still in the shipping post box from 2022. Whatever work was bought and paid for didn't last the test of time in the box from the UK.
Thanks, - Tom