Hi, My PC recently went kaput. No life at all, PSU stank of electrical shorting, so got a new one. When I connected the new PSU in and connected the mains, the PSU and CPU fans immediately span up (without powering up the PC), but nothing else happened and the PC remained dead. Removed all drives, cards (including vid), and memory. So just got motherboard and CPU. The symptoms are the same - plug the PSU into the mains and the PSU and CPU fans spin up, but nothing else happens. I've taken the board out and placed on wooden surface, and the same happens, so it's not the board shorting to the case. It's easy to speculate that one of the other components now removed, by its absence or fault, causes this behaviour. But I think it's more likely that the board or CPU is dead (can't tell which I don't think?), taken out by the original PSU when it went. Can anybody with experience confirm that this is the most likely case? That it's the board and/or CPU, rather than a fault in / absence of one of the other components? I want to order some replacement kit, but want to have reasonable confidence that I've narrowed the problem down correctly! Thanks
sounds weird, i know fans twitch when power restored (not powered up, turned on) but fans going continually when power restored (still not turned on) is wierd, try a BIOS reset & it could solve all your problems, good luck xxx
Okay - how do I reset the BIOS with no POST and no video output? The ONLY thing that happens is that the fans spin. The PC does not switch on!
Depending on the dead power supply, you may or may not have had a few other parts go with it. Speaking of the power supply: I know you're using a different one, but if it doesn't have enough amperage, you also might not boot. i.e. If you were using a 500W Antec power supply and are trying to use a 300W Coolmax unit, and you've got a fairly recent system, that's probably why you're not getting a power up. To Clear CMOS, you should have a 3-pin jumper with a jumper cap covering two. With the system off, you'll move the jumper from shorting pins 1-2 to pins 2-3 for about 5-10 seconds. For the location of said jumper, you'll have to consult your motherboard's manual. Failing that, you can remove the CMOS battery on the motherboard for 10 seconds or so and replace it.
That's what I figure. As the behaviour of the fans is the same whether I've got a bare board or a populated one, I'm assuming the fault lies with the board... I replaced the PSU with a higher-rated one, so that shouldn't be a problem. The system is about three years old, and the original PSU was rated at 250W. The new one is rated at 300W. Should I be doing this with the power supply connected (ie. fans spinning but nowt else happening), or swap the jumper, then apply power for 10s? Thanks for the advice!
only do a BIOS reset with the power turned off (remove the power cable) if you don't have an anti static strap just touch an expose metal part of the pc case (while playing inside it) the pins are located near the battery (big watch battery) if you remove battery do NOT use metal tweesers EDIT: it could be that the battery is dead, don't worry there not expensive, most computer shops sell them
Okay, thanks for that. To go back to the original problem though -- do you think that the motherboard is kaput, bearing in mind the symptoms I related in my OP?
Okay - I removed power, changed the jumper, restored power (same symptoms) for 10 or 12 seconds, then removed power, put the jumper back to its 'Normal' state and plugged the power back in. No change in symptoms! Any other hints? I'm desperate to get this fixed, but want to be as sure as possible that I'm replacing the right parts! Thanks!
no, keep the power off until the BIOS reset complete, restore power when after you've put the jumper back on pins 1 & 2, then try it
