I recently acquired a 5150. It is a 16-64k with two drives and color. I have
not been able to boot it up yet. I cleaned the inside, and made sure
everything was well connected. When I flick the power on, the CPU fan goes,
and nothing else. There is power coming out of the motherboard and drive
connectors, but there is nothing at the ISA slot. No beeps or anything. I
Perhaps I am misunderstanding you, but surely if you're getting power at
the power output connectors of the PSU, the fault is not in the PSU.
-tony