I've put this under "Build Advice" because I'm not sure what's up. I shut my computer down yesterday evening, pushed the power button to turn it back on again and nothing happened. I've tried the on-board power button, tried unplugging the front panel button and just using the on-board one, still nothing. So I don't think it is the power button! After being left overnight unplugged, nothing has changed, I've tried playing with the BIOS reset jumper and that has done nothing either. When the computer is plugged in, the standby light on the motherboard comes on, but that's all. No bleeps, no other lights, no change when the power button is pressed. Gut reaction is that the PSU has gone but before going out and buying a new one I wanted to check if anyone had any other suggestions? Getting a spare to try will be tricky, I'd have to persuade a friend to let me dismantle one of their computers and getting all the cable management back properly will take a *long* time. tia edit: just noticed that my PSU isn't in my sig, it's a Hiper Type M 580W - you can probably guess why I think that's the problem!
To check your power supply, first unplug everything, and then use a paper clip to momentarily connect the green wire of the mobo plug, to any of the black wires. It won't hurt to confirm that the power lead and the power point work btw! If it won't turn on, it's dead... but you might aswell try with a dvd anyway, just so it has a load... Disconnect and repeat the test with the dvd plugged in, and see if the dvd tray works.... it would also be best to check the voltages with a multimeter or a psu tester of course, but you could just try your luck and continue trouble shooting... It won't make things worse to try the psu with the mobo again, but this time leave everything unplugged, as in hdd, gpu, soundcard, etc. Nothing but mobo and cpu, and see if the psu powers up - if it does, check the voltages in bios - they aren't always accurate however but they are usually good enough to show any problems... so moving on... If all looks good, then you can try powering down, and connect one component, test, repeat, untill you find the culprit.
Could also be worth shorting the battery to reset the bios, should be a jumper nearby. In case you've not done it before: Check your MB manual to be sure it's the right one, then swap the jumper to the other side (so if it's on pins 1 & 2, put it on 2 & 3) for about 10 seconds then make sure you put it back before trying to start the computer again.
OK, there's a voltage of 5V between the green one and black immediately after it has been plugged in. If I short that, a quiet high pitch "cheap, cheap, cheap" noise stops, the fan starts and the voltage drops to 4.5V. I then went around testing all the others with relative to black, one other was 4.5 and the rest were 0, the DVD drive did not respond. Right, I guess I'll be looking for a new PSU then, anyone got a second hand one they want rid of?
I've managed to borrow another (rubbish and old, but working) PSU to test my computer with. It started starting up, so I've bought a new one to replace it with, a Thermaltake Toughpower XT 650W which JonnyGURU seems to rate. Thanks for the help Bit-tech: why no recent PSU tests? That said, the ones over there are pretty good, there's nothing really you could add I don't thing. edit edit: So, despite saying that they had it in stock, Scan were lying. This was clearly malicious instead, I found that I could pay not all that much more for a modular XFX XXX somethingorother, 650W based on a Seasonic. That arrived today, has been installed and is working perfectly. Woop.