With vaguely similar symptoms, stripping all the way down on MB [almost..]: no POST doornail-dead.

But I'd stared right through: a *&$%@ cache plug-in chip, which another eyeball Noticed. It was *that*. The LAST thing removable.

As you have swapped both PSs AND MBs, etc. already - just maybe you have a cockamamie AC power distrib, as Box suggests. (As in - when ALL hi current stuff in a house is plugged in on one side of the 220 split pairs) Grounding alone - I would doubt.

It's really ODD about those fans not starting - as is it odd to have more than One thing broken..

It also can't hurt to measure a few of those DC voltages from new PS -- starting with the EZ place -- any cable has 5V, 12V jacks. This since,now you must doubt either the new PS OR the new MB/CPU combo (though you also swapped CPUs). I think you still cannot test your switcher without a nom. load on at least one of its PSs ie not naked (?) (Outside the el-cheapo computer ind. there are sometimes ballast resistors to enable the PS)

Jumpers wrong for CPU Lo-V/Hi-current section? = might also crowbar (not destroy) whole PS section. Any other PS problem will fail the MB POK (Power OK) line. I think.. that also would inhibit POST ever starting. Check every MB jumper in the cute manual?

Lastly - how is the new MB grounded to the case? This is usually supposed to be ONE HD termina/screw with teeth to make a good one-point ground / avert ground-loops. All the rest want to be (usually) insulated physical mounting points (only).

'Pologies if this is all old stuff,


Ashton