One of the PCs in my office stopped working the other day and now does absolutely nothing when you press the on switch, no lights, no noises, absolutely nothing. However, when you unplug the cable from the back it makes a faint high-pitched noise which gradually dies away.
I've replaced the power pack with one I know is good, reseated the RAM etc but it still doesn't even POST.
The motherboard is an ASRock G31M-VS and the PSU in there at the moment is an LPJ12-450W. The other PSU it had before which is now working fine in another PC is a P4-450W.
It's not really a squeal, it's a very high-pitched, faint tone which lowers in pitch and disappears over a few seconds. It just seems strange to me that even the power light on the switch doesn't come on. If it was bad RAM or something it would still at least have lights, no?
I inherited the PCs in the office/Internet cafe when I took over the place, an ecolodge resort in rural Laos, and getting anything of quality here is somewhat tricky, especially technological stuff! They're only for guest Internet use etc so they don't need to exactly be top notch!
So a fried motherboard would mean no lights or anything yes? If so, I'll pick another one up next time I'm in town, they're not that expensive here but that's probably because they're cheap stuff imported from China...
Again, a known working psu that won't power another mobo (especially in a system that *was* working) shifts the odds dramatically to "mobo problem". Theoretically, it is possible it could be something else, but its not very likely.
Sorry for your difficulties - and the working environment - but I'd encourage you to do your best to ensure you're using a psu of minimum quality. If you get a cheap mobo and it fails prematurely, the odds are good it won't kill anything else.