C1569 seems fine, and the -8V supply is also good.
I just realised that I confused your thread with another current thread: "Introducing myself and my Tek 465 Project". The problem 'scope in that thread has the -8 V problem
The manual seems to specify that Q1514 is there to protect the +120 V supply, and that if it fails,
it may cause problems:
My manual (070-1330-00) states that "This circuit provides protection in the event that the applied line voltage exceeds the upper limit selected by the Regulating Range Selector Assembly. It seems that +55 V unreg. is used to detect and trigger at such overvoltage.
If your line voltage is within the selected range and the caps are ok, I don't see what could cause overvoltage and not much that you could do about such a situation. If it really disturbs you, you may select the 120 V (H) position and see if there's still enough regulation range. I bet there is.
I just opened a 465. Running on 230 V, range set to M, as it should, 120 V (unreg) is 151 V.
I wrote this and it's confusing. The 465 I opened is a B250000 & Up version, which does not contain Q1514 with its related circuitry. OTOH, the transformer and unregulated circuits are very similar with the same component numbers so I wouldn't be surprised if "120 V unreg." would have about the same value....
My apologies.
Raymond
Raymond Domp Frank