PC automatically powers off

darude · 19 Dec 2009 at 12:48

Hi all,

Recently my PC starts to power off by itself - without warning.

First signs: powering on the PC using the power button on the case doesn't always turn it on. I thought this was the motherboard battery, so I replaced this, but had no effect. I tend to turn off the switch on my wall socket every night, but if I leave it on, I have a better chance of turning on the computer with the case power switch.

So when does it turn off?
- First time was when I booted to XP and it turned off when I was browsing network files
- So I thought maybe its a network issue, unplugged the ethernet cable, boot up to XP again, and then it turned off when I browsed HDD files.
- So maybe HDD issue, unplugged all HDDs, boot up to BIOS setup screen, and then it turned off there

Any idea what it could be? The CPU temps looks ok in BIOS, under 40c. Fans all running ok. Turning on the PC with the case power switch doesn't always turn it on now. PC can stay on for about 2/3 mins in BIOS setup.

I don't play games often, perhaps once every two weeks for an hour.

Any ideas guys? Spec in my sig below...

darude · 19 Dec 2009 at 13:41

Thanks, I might be able to find another PSU to test.. will let you know the results later...

When I replaced the motherboard battery the BIOS reset, so CPU has no overclock.

darude · 19 Dec 2009 at 16:00

Thanks all, you guys are right, the PSU is the problem.

I've put in a Akasa 400w from another PC and it boots up and run XP no problem. Now, the Tagan couldn't complete booting up Windows.

Some screenshots of the BIOS hardware monitor below:

Akasa (working PSU)

Tagan (faulty PSU)

Time for a new PSU, any recommendations?

darude · 19 Dec 2009 at 16:19

Thanks Alex, are Antec PSUs any good? Modulars are always nice:

http://www.overclockers.co.uk/showproduct.php?prodid=CA-111-AN&groupid=701&catid=123&subcat=1088

And yep, I have plans on upgrades soon, but no SLI or crossfires.

darude · 19 Dec 2009 at 21:25

Funny enough the Tagan PSU seems to work ok in a different PC. Specs: Intel Pentium E6300 Dual-Core 1.86GHz, 1GB RAM, Abit IP-95 without any overclock. I don't know how long it will last though. :confused:

EsaT said:
Depends on which one you're looking at.

Basiqs are their lowest quality PSUs and might be all FSPs whose PSUs are mediocre at the best and often contain random quality capacitors. (500W Basiq is exactly such)
TruePower New models are probably made by Seasonic and have high quality parts.
Signatures are again high end Deltas.

You sure know your PSUs EsaT. This TruePower New Modular looks like a very nice option.