PSU should be good. It hasn't been outputting peak loads (or indeed, anything beyond idle load) since the computer failed.
But attempting to operate the computer without plugging in all the ATX power connectors could cause all sorts of problems, though - motherboard hardware damage (burnt VRMs, blown caps, etc), corrupted motherboard firmware (bad BIOS), it could even kill the processor and/or PCIe card(s). Your mobo Q-LED suggests the problem is a component on the motherboard power regulation, not the power source itself.
You already unplugged the PSU, removed mobo battery, waited half a minute, Cleared CMOS, yes? Were you able to boot far enough to reflash a BIOS? Does the other Dual-BIOS segment boot up? Does any components feel really hot, smell burnt, make noise, or seem to act strangely when the mobo is powered on? Can you spot any damage on the motherboard with a careful visual inspection?
Try the
advice on this thread. If that fails then you'll have to dismantle your hard tubing anyways while you strip down to hardware troubleshooting ... or you end up finding no other faults and replacing a dead mobo.
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[/Korth]
