No power to pc

[Yohji]

Hey guys,

Looking for advice on next steps - I'm not getting any power to the computer, so it will not turn on at all. My first guess is that the PSU is dead? I've checked and can't see any loose connections to the motherboard.

(And yes it was definitely turned on at the wall )

Any suggestions welcome.

[kompukare]

Well first things first: do you have any way to check your mains lead, it's fuse etc.? Even an old fashioned kettle might do (although careful since a lot kettles need the full 13A whereas some computer leads might have a 5A fuse: so if you try a 5A lead in a kettle it might blow).

Next, is the PSU fan coming on. Does the mobo have any LEDs and if yes are they lighting up - in which might point to the case's switch not working of the lead from that switch being bad. PSU's can be started disconnected from the mobo and all peripherals by shorting pin 14 and 13 but you might not be comfortable with that.

[Thorsson]

You said it was turned on at the wall, but what about the PSU switch; is that set to 1?

Motherboards usually have lights; are any coming on? What about the PSU itself, some of those have lights? This is with the PSU switched on but before you push the Power Button. If there are lights but nothing comes on it suggests that there is a problem with the PSU.

Do the fans spin for a fraction of a second when you push the Power Button? Or is there no sign of life at all? If they start to spin and then stop this suggests a short.

[Yohji]

The PSU fan isn't coming on - but there is an LED lit up on the motherboard... The cable for the case's switch doesn't seem to be loose though.

[kompukare]

Well LED on the mobo just means that the 5V trickle from the PSU is working. However, the PSU could still be dead or the switch. That the cable from the switch isn't lose doesn't really mean that much: the cable could be fine but the actual switch on the case could be gone.

But all that switch does is short the two pins it goes into: the switch doesn't stay 'connected' - in fact if you were to short them for 4 secs on a working PC that PC would turn off again. So you can remove that cable and carefully short them yourself with a small screwdriver.

[Thorsson]

The PSU fan isn't coming on - but there is an LED lit up on the motherboard... The cable for the case's switch doesn't seem to be loose though.

Any board fans starting? Like the CPU fan or chipfan? Have you checked all power cables, the seating of all cards and RAM? Any loose connections can cause a short.

Assuming these are OK the most likely culprit is still the PSU, but to confirm I'd disconnect everything from the PSU power cables except motherboard & cpu and one stick of RAM. If that shows more sign of life add back the video card. If that starts to boot (failing on no boot disk) you can start to add stuff back one thing at a time. If it doesn't then probably the PSU is no longer supplying enough 12V, but if you can swap out for an old video card that would confirm that, as a faulty card could also cause the problem.

[fazer]

Check this guide out if your savvy with a multimeter and electrics, this will determine once and for all if your PSU is dead.
http://www.huddysworld.co.uk/index.p...psu-is-working

[grayg1]

You could do a test using a paperclip and a case fan like this http://www.youtube.com/watch?v=5FWXgQSokF4

[Yohji]

Well I feel silly now... Checked the case power button again and it had come loose but not at the motherboard end!

Thanks for all the advice though, much appreciated

[Thorsson]

What's your case (so we know to avoid)?

[Yohji]

It's an Antec three hundred!

[Thorsson]

LOL. Mine's 3 years old now and haven't had a problem. You been yankin' on it?

[Yohji]

I cleaned it out a few weeks ago, so must have gotten dislodged when I put the front back on. Strange it took so long so fall out completely.

Still, pretty decent case as it was fairly cheap and I've had it nearing 5 years.