I was working on my PC, and suddenly it just switched off, no screen freeze, no blue screen, just switched off, as though the power cable was pulled out. I tried to turn it back on but it wouldent turn, tried removing the main PSU-motherboard connector and reconnecting but nothing worked. I left it till today after I came back from work to check if it would start working again, but still, no reponse from pressing the on button at the front. I think one of two things may have happened, an insect or something flew into the PC case, and shorted something inside the PSU, or the PSU has just burnt out (Incase you want to know what it is, its a tagan 580W, ive been using it for about 3 and a half years now and its been working flawlessly). How do I diagnose the problem so that I know which part is faulty? Is there anyway at all to test the psu to see if its working? Or is there anything anyone on here can recommend which might fix the problem if its not a burnt out PSU?
PS, here is the configuration of the PC.
Intel E8400 @ stock voltage and speed
Gigabyte GA-EP35-DS3L Motherboard
Twin maxtor 250gb HDDs
2x2gb Corsair xms2 ram sticks, running at 800mhz
nVidia 9600GT 512mb gfx card
Tagan 580W psu (3.5 years old, running flawlessly since purchase)
Try to verify (well as you can) that the PSU works. If you have a multimeter, you can do a rough checkout of a PSU using the "paper clip trick". You plug the bare PSU into the wall. Insert a paper clip into the green wire pin and one of the black wire pins beside it. That's how the case power switch works. It applies a ground to the green wire. Turn on the PSU and the fan should spin up. If it doesn't, the PSU is dead. If you have a multimeter, you can check all the outputs. Yellow wires should be 12 volts, red 5 volts, orange 3.3 volts, blue wire -12 volts, purple wire is the 5 volt standby. The gray wire is really important. It sends a control signal called something like "PowerOK" from the PSU to the motherboard. It should go from 0 volts to about 5 volts within a half second of pressing the case power switch. If you do not have this signal, your computer will not boot. The tolerances should be +/- 5%. If not, the PSU is bad.
Unfortunately (yes, there's a "gotcha"), passing all the above does not mean that the PSU is good. It's not being tested under any kind of load. But if the fan doesn't turn on, the PSU is dead.
I have a Enermax PSU that has a built in protection for power surges. If it shuts down like that I have to switch it of on the power switch on the PSU itself to reset it. Just wondering whether you tried that?