H7868 Power Supply Schematics

[Antonio Carlini]

I have a non-functioning H7868 PSU. This is one of the two PSUs used in 
a BA214 chassis (and probably elsewhere).

This one seems to be dead: the green LED doesn't come on at all, there 
is no sign of life and no +5V appears on the BA214 Qbus.

(I did use a load board when testing, so that's not the issue).


Does anyone have a set of schematics? I did try poking around in the 
various MicroVAX 3600/3800 schematics that I could find on bitsavers but 
nothing obvious leapt out at me. Of course, I could easily have missed 
something.


Alternatively, does anyone have any experience of working on these PSUs? 
Any pointers for common failure modes would be helpful.


Thanks


Antonio


-- 
Antonio Carlini
antonio at acarlini.com