Computer won't start, unsure if PSU or motherboard is causing it

yerjam

yerjam

yerjam

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28 Feb 2012
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Location
Northern Ireland
Hi all.

So starting on Thursday my PC started turning off randomly. No BSOD, no nothing, as if it had just been switched off at the wall. It would turn off even when I wasn't doing anything particularly taxing like when I was just browsing the web. I checked the temperatures and they all seemed fine, nothing unusual. Eventually it kept happening more and more. It got to the stage where my computer would only stay on for about an hour and then just randomly turn off. Again, no BSOD or anything.

Now it's got to the stage where my computer won't boot. When I press the power button everything lights up and fans start spinning but it shuts off again after a second or so. I've narrowed it down to either the motherboard or the PSU. Here's some things of note:
  • I checked all the cables and made sure they were all attached properly and weren't damaged. Everything appears to be fine.
  • I've cleaned the dust out of the system.
  • I reseated the CPU and replaced the TIM. This worked for a couple of hours but eventually the computer stopped booting again.
  • There are no scorch marks on the motherboard or anything that would indicate extreme overheating.
  • Although the DrMOS overheat LED turns red when I try to turn the system on.
  • The system is not on long enough to enter the BIOS
  • I have an 850W PSU which is more than enough to power my system.
  • The only recent change to the system was the addition of an extra SSD for RAID which required a clean install of Windows.
  • The temps I was getting when this started happening weren't anything abnormal.
  • This motherboard has given me trouble before; when I first got it it used to go into an endless reboot cycle. This was fixed by reseating the CPU. Also the CPU fan header stopped working randomly.

So what do you guys think? I can't narrow it down to anything else other than a faulty motherboard or a faulty PSU. Is there anything else I should try?
 
psu's can degrade and die or simply not provide enough power over one of the rails ect

would be good if you could try n borrow another to test with
 
How old is the PSU?

But as said ^, try another PSU if you can get one to test.

Also could you try running something like HW Monitor in the corner so you can constantly see the temp if it's spiking?
 
wazza300 said:
psu's can degrade and die or simply not provide enough power over one of the rails ect

would be good if you could try n borrow another to test with
Click to expand...

This won't be possible. I have no-one nearby who I could borrow a PSU from. Is there a way I could test the PSU?

Scotteh said:
How old is the PSU?

But as said ^, try another PSU if you can get one to test.

Also could you try running something like HW Monitor in the corner so you can constantly see the temp if it's spiking?
Click to expand...

The PSU will be one year old at the start of May.

My system won't stay on long enough to even get into the BIOS let alone run HW monitor I'm afraid.
 
Google psu paperclip test

It's still not 100% guarantee though,you can only go through each component,tried with only one ram stick installed?
 
wazza300 said:
Google psu paperclip test

It's still not 100% guarantee though,you can only go through each component,tried with only one ram stick installed?
Click to expand...

Yes I've done this and the same thing happens.

Is there a safe way to do the paperclip test without a paperclip? Unfortunately I don't have one handy. If not I can get one tomorrow.

Scotteh said:
You can get PSU testers but they're typically about £30, if you have a multimeter;

http://pcsupport.about.com/od/toolsofthetrade/f/powersupplytest.htm



http://www.corsair.com/en/blog/testing-your-corsair-power-supply
Click to expand...

Thanks for the links, like I say I'll need to source a paperclip (something you'd expect everyone to have around but I don't ffs lol). I'll get started on testing the PSU as soon as I can.

Based on everything I've said, do you guys think it's likely to be the PSU? I was leaning towards the motherboard based on the issues I've had with it in the past.
 
Can't really say, as it could be the mobo powering up then failing or the psu failing to supply the required power

But if you've had issues with the mobo before, i know where i'd be pointing my finger.

Test should let you know for sure though :)
 
Scotteh said:
Can't really say, as it could be the mobo powering up then failing or the psu failing to supply the required power

But if you've had issues with the mobo before, i know where i'd be pointing my finger.

Test should let you know for sure though :)
Click to expand...

Thanks, I'll update this thread once I've tested the PSU.
 
you can test the psu with the paper clip test but it wont be the be a test that will tell you the psu works or soesnt work as the psu might turn on, but it's under no load and doesnt have to power anything so the only way to "really" test it is either using another psu in your system or putting it in another pc. To me it sounds like a dodgy motherboard as the cpu fan header isn't working and reseating the cpu fixes it for a while
 
Thanks for all your help guys, I found the problem. I done the paperclip test and the PSU is working fine. So naturally I assumed the motherboard.

I managed to acquire an old motherboard I had in my grandparents house and used this to check the PSU for sure. I hooked everything up and it ran fine, POSTed, booted and stayed on instead of instantly turning off.

I'm in the process of RMAing the motherboard.
 
yerjam said:
Thanks for all your help guys, I found the problem. I done the paperclip test and the PSU is working fine. So naturally I assumed the motherboard.

I managed to acquire an old motherboard I had in my grandparents house and used this to check the PSU for sure. I hooked everything up and it ran fine, POSTed, booted and stayed on instead of instantly turning off.

I'm in the process of RMAing the motherboard.
Click to expand...

glad you got it sorted
 
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