How to diagnose a problem?

[Jimmeh]

My computer just died and I have no idea why.

Basically I was playing Bad Company 2 when the PC just cut out, switched itself off, no shut down procedure or anything, just a sudden stop.

Usually when my PC is switched off but still plugged in, there is a light on the motherboard that constantly stays lit, but it is nowhere to be seen at the moment, even if the PC is connected to the mains.

So I'm just wondering, how do you tell what the problem is with a computer? How do I tell if the PSU has died, or if its the motherboard, etc?

 

[jamesd1981]

you would need a digital power supply tester, but most people dont know have that kind of equipment unless they do it as a job, a simple way is if you have or can loan a working pc try swapping a piece at a time, like eliminate the power supply by attaching to a pc you know works if it doesn`t power up you know the psu is dead, and so one piece at a time

 

[PohTayToez]

Sounds very much like a power supply failure. The only way to know for sure is to test the power supply with a tester, or to simply replace it.

EDIT: Whoops, looks like james beat me to the punch.

 

[jamesd1981]

Sounds very much like a power supply failure. The only way to know for sure is to test the power supply with a tester, or to simply replace it.

EDIT: Whoops, looks like james beat me to the punch.

you get the credit for direct tester purchase link

 

[Nanobyte]

The light could be a number of things but most likely is the Standby LED. No power is the most obvious issue as already pointed out. However, have you tried turning the PSU mains breaker off and then on again? The PSU may lock out on any major failure and needs the power off to reset.

 

[Jimmeh]

Thanks for the replies.

Nanobyte: I have tried completely unplugging the PC, therefore cutting off any power, however it didn't seem to help, still as dead as it was.

James: Unfortunately I don't have access to a second desktop PC, so I don't actually have any way to test the components by switching them out.

 

[Nanobyte]

Last resort - one basic check is the paper clip test (or get the PDF of the test here). You have to disconnect the PSU from the MB. If it does not power up and its fan run, get out your wallet.

 

[Jimmeh]

Well Nanobyte, thank you so much for that. I did the paperclip test and it didn't work. So I'm guessing that I need a new PSU

 

[Nanobyte]

See, you should have listened to Jamesd1981 and PohTayToez! Most people seem to stick the new supply in without making any checks (which is insane if you are on a 240V supply or have an expensive MB). I call that Plug 'n Pray. You can find the PS main connector pinout by googling. Paper clip test and use a digital multimeter if you have one; a neon mains tester if you don't. Otherwise, pray.