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Failing PSU?

Posted: Sun Nov 18, 2012 4:02 pm
by Stephen
About two months ago I was on my computer (its a dyi - about mobo, hsf, and psu about 5 years old, other components are newer) when it suddenly shut down. I then pushed the power button and nothing happened. I unplugged it, tried to turn it on and again nothing happened. I then tried a third time and it booted up fine. CPUID show temps are all fine.

It was then fine until a couple of weeks ago when it started again. Now it will stay on for about two hours, then shut down. Yesterday my burner stopped working, though Plex Utilities can find it. Today my DisplayPort connection stopped, and I had to connect the graphics card with the DVI connection. Temps seem fine. I'm guessing it's the PSU.

I'm getting ready to do a new build, and I'm hoping to use some of the parts from the oold computer. Is there any way to tell if the failing PSU has done any permanent damage before installing them in the new compujter?

Re: Failing PSU?

Posted: Mon Nov 19, 2012 1:40 am
by edh
That sounds like some sort of thermal shutdown issue. Something gets too hot, cuts out and only once it has cooled down again are you able to switch it back on. One hypothesis could be the PSU but equally something on the motherboard or graphics card could be at fault. Have you done any temperature monitoring with Speedfan? Set it logging and see if anything comes up when reviewing the log after a shutdown. It may well be fixable.

Re: Failing PSU?

Posted: Mon Nov 19, 2012 8:20 am
by Stephen
edh wrote:That sounds like some sort of thermal shutdown issue. Something gets too hot, cuts out and only once it has cooled down again are you able to switch it back on. One hypothesis could be the PSU but equally something on the motherboard or graphics card could be at fault. Have you done any temperature monitoring with Speedfan? Set it logging and see if anything comes up when reviewing the log after a shutdown. It may well be fixable.

Temps are all showing fine.

Re: Failing PSU?

Posted: Mon Nov 19, 2012 9:35 am
by washu
Any bulging / leaking capacitors on the MB or video card?

Re: Failing PSU?

Posted: Mon Nov 19, 2012 5:13 pm
by Stephen
washu wrote:Any bulging / leaking capacitors on the MB or video card?
Nope.

Re: Failing PSU?

Posted: Tue Nov 20, 2012 2:54 am
by edh
OK then. Another diagnostic. Does the motherboard have a power LED on it somewhere? They're quite common although may be very small. With your computer off, see if the LED is illuminated. Then use the computer until it cuts out. Now look at the LED again. If it was on before but is not on now then the problem is definitely PSU as the motherboard is no longer receiving power.

Do you have access to another PSU (borrow one?) to test against?

Re: Failing PSU?

Posted: Tue Nov 20, 2012 7:57 pm
by Stephen
edh wrote:OK then. Another diagnostic. Does the motherboard have a power LED on it somewhere? They're quite common although may be very small. With your computer off, see if the LED is illuminated. Then use the computer until it cuts out. Now look at the LED again. If it was on before but is not on now then the problem is definitely PSU as the motherboard is no longer receiving power.

Do you have access to another PSU (borrow one?) to test against?
I checked and the LED was lit before and stayed lit after the computer shut itself off.

Sometimes it stays on for a couple of hours, other times half an hour or so.

Re: Failing PSU?

Posted: Wed Nov 21, 2012 1:47 am
by edh
Could well not be the PSU then. Borrow another PSU to check.

Re: Failing PSU?

Posted: Mon Dec 03, 2012 3:51 pm
by Stephen
Ok, after I pulled out the harddrive without the OS and pulled out the soundcard, the computer is fine. It's been running for 36 hours straight without any issues. What gives?

Re: Failing PSU?

Posted: Tue Dec 04, 2012 1:03 am
by edh
So now try adding the soundcard back in. You need to work out which component it is, this is exactly the same principle as an exclusion diet used to find food allergies!