Sun4 370 PSU Maintenance/Schematics

[aswood at t-online.de]

Hello all,
 
I do have an Symbolics UX1200 plugged into a Sun4 370 host.
 
Before powering the host, just to be secure, I'd like to check the psu - or 
if the psu will be broken, I'd like to try to fix it.
Yesterday I'd a look into the psu - very complicated layout!
 
Is there any known documentation, servicing and maintenance documentation 
or schematics for psus used in Sun server/workstation available, of course 
esp. for psus used in Sun4 370 systems?
 
-- Andreas