Next problem w/ as8200 /tru64-Server

Hello Admin Wizards,

offtopic, but in hope of an answer:

I obviously was all too optimistic about the AS8200. After running 
smoothly the last three weeks, today I found the system stone dead.

First I thought about a power failure, but the power is on and all other 
servers are still running.
Now I am trying to encircle the problem and I suspect the Power Supply 
Unit (30-41523-01) to be the problem.
Now my question:
If one connects the PSU only with the power outlet in the wall (240 V) 
and nothing else, and switch on the circuit breaker on its backside, the 
cooling fans are supposed to run, aren´t they? I think I remember that 
these went on when I assembled the machine.
At the moment, they dont - this leads me to the suspicion that the PSU 
is gone, however, I have no idea why - the log of the USV on the 
mainserver shows no irregularity.
I just want to be sure about this before buying a new one or have the 
old repaired without being sure that the rest of the system is ok.

Will be grateful for every opinion on this

CW