PC automatically powers off

darude

darude

darude

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Joined
30 Oct 2005
Posts
196
Location
Birmingham
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...
 
Tried it without the overclock? May have become unstable as the hardware has aged.

Also could very possibly be a power supply issue. Do you have another to test it with?
 
If it's just turning off on its own then it's more than likely either going to be the psu or mainboard (dry joint maybe).

Like Alex said have you got another psu or could you borrow a psu to test?
 
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 said:
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.
Click to expand...
So "cold" boot is more problematic.
Could hint to capacitors either in motherboard or especially PSU's 5V standby whose problems show directly in boot up problems.
(because motherboard needs it to be able to tell PSU to start when you press power button)

Well, ToPower isn't exactly high quality maker and uses also grab bag caps.
If you don't have other PSU to try detaching PSU completely and opening it could tell are capacitors bulging/leaking which are signs of guaranteed failure.
 
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?
 
I'd recommend something that'll last you a long time and that you could move over to your next PC (you can't keep that Pentium D forever can you!). Think of it as an investment, a good PSU is extremely important to a build.

Depending on budget, you could do as above, or just go cheap for now.

Cheap for now (but good quality of course) is this.

Something more sensible for the future - here.

Of course, if you have upgrade plans you may even want to spend more on something more powerful with real scope with SLI or Crossfire.
 
darude said:
Thanks Alex, are Antec PSUs any good?
Click to expand...
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.

alexhull24 said:
Something more sensible for the future - here.
Click to expand...
And that one precisely isn't sensible with all those cheap Chinese grab bag capacitors.
I haven't yet seen OCZ with high quality parts.
 
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.
Click to expand...

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