old PDP/DEC PSU hardware question

[Dr Iain Maoileoin]

I have a query out on VCFed, but I am not gettin gany interest.  Neither did my 2015 request on a similar topic - must be the wrong forum.

Advice please: where is the best place to get some troubleshooting tips on debugging a DIGITAL H7202B power supply?
I have 2 supplies that are giving me trouble.  I am competent at digital work, much less so on switch-mode and analogue
(555 is an analogue in my books!).  I have variacs  scopes, logic analysers, voltmeters but no skill ;-(

Any advice?