Have you got a multimeter to test the PSU first? Or whack the PSU into another PC if you've got one and test it there.
Erm
12V - 14.8V
5V - 8.4V
That does not look good.
Different PSU, same behaviour. But that wouldn't surprise me if the original PSU has killed something with its high voltages
RAM is still alive, as is the main system hard drive. I wonder if just PSU and motherboard will sort it.
Have you checked the voltages on the other psu? If they're out as well it could be heavy electricity.
Oh, here's a thought.
Have you tried checking the voltages with the bathroom light off?
Other PSU is near enough to 12 and 5. Bathroom light has been off. I'll try with it on.
Always helpful Kos. (fail)
Did you check the voltage with a load attached? No load on a switched mode PS is going to give squiffy voltages, so may not be the psu that killed it.
(ant's old (old old) bathroom light used to knock out his Internet when it was switched. We cling on to the past round here, it keeps us from noticing how devoid of exciting newness our lives are)