Power supply turns on but motherboard and rest of computer do not.

inneruniverse

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Jan 22, 2015
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Hello. I have been having a problem with my computer for months. The problem is in the morning when I go to turn it on for the day, I push the power button on my case and the power supply turns on, but the motherboard, CPU fan, Case fans, etc all do not turn on. The only thing that turns on is the power supply. If I unplug and replug the motherboard power cable or just fiddle with it for a bit I can finally get the rest of the machine to power up.

Once powered up, it stays that way the entire day unless I put my computer to sleep. If I put it to sleep there's a chance it won't wake up and I have to restart the fiddling process all over again.

The motherboard cable does not snap in, it just pulls right out, so I was thinking it's possibly a loose cable. I have a FirePower ZT Series 750W PSU that has been in my machine since 2012. It is still technically under warranty but I don't have the original receipt (have the e-mail though) and I'm afraid they would take a month to RMA so I just went and bought a new PSU.

Does this sound like a power supply issue? I already ordered a new PSU but I'll return it if it does not solve the problem. If it's not a PSU issue, what else could it be and how should I go about troubleshooting this?
 

syked3

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Jul 7, 2015
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Try the paperclip test on PSU, it is not a definitive test but it should give some indication of where the problem lies. As rolli59 said, if the PSU is working then the motherboard is culprit
 

inneruniverse

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Jan 22, 2015
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I don't think the paperclip test will help because the power supply always turns on and that test is just testing to see if the PSU will boot. I am worried now that it could be the motherboard because the PSU always spins up even though the rest of the machine does not.

Is there any way to test if my motherboard is failing?