Straight WD40. The issue was simply where the shaft goes through the brass bushing on the front of the potentiometer body, so purely a mechanical issue.
Thanks for the service manual link.
A closer look at the innards suggests one or more of the 3 big caps on the PSU are leaking. Any views on...
Hello folks.
I had the opportunity of being gifted a Telequipment D83. After freeing a gummed up power/intensity control (WD40 and brute force) It seems mostly ok, powering up and with a nice bright in-focus trace.
There were a few loose grubscrews in knobs and some internal control linkages...