A mysterious power problem

[PhoenixSP]

Good Afternoon,

I have a mysterious problem with my PC where occasionally when turning it on nothing happens, the whole system is dead however if i wait about 10 minutes the system powers on like there is nothing wrong and then works happily until it happens again.

The PC is switched off via a power strip when not in use and when it doesn't turn on there is no activity at all in the PC


any advice ?

 

[ExRayTed]

Disconnect the cable from the case button to the motherboard then try shorting the jumpers out a few times. If the problem goes away it my be the power button on your case.

 

[Rroff]

Does anything happen at all? i.e. do the fans spin for a moment and/or LEDs come on or is it completely unresponsive?

 

[PhoenixSP]

I will try shorting the jumpers later today , im pretty sure its not the power button though as its not like i have to keep pushing the button its almost as if the pc doesn't like starting in the cold.

Nothing happens at all completely silent, unfortunately my mobo has no lights to indicate life ,but the fans don't move and the psu fans don't come on either.

 

[ExRayTed]

Probably a dying power supply then.

 

[WalderX]

Probably a dying power supply then.

Yeah what make/model is the PSU and how old?

 

[PhoenixSP]

Apologies for the late reply as the problem is sporadic i can only test things when it misbehaves. However the problem is getting worse and more frequent and have had other issues like attached usb devices turning on and off (eg mechanical keyboard back light flickering then turning off , then coming back on again.

ive confirmed its not a power button problem as there doesn't appear to be power to the board until it fixers itself as it doesn't show up on my switch until it has power.

PSU is an XFX 750W XXX Edition Modular '80 Plus Silver' Power Supply that is just over a year and a half old now. I find it strange that the problem occurs randomly though its generally when turning it on for the first time in a few hours.

 

[PhoenixSP]

Any suggestions on what to do next , im assuming i will have to bite the bullet for a new hard drive depending on how long it takes for warranty assuming its more than a year and if its possible to prove an intermittent problem.

 

[Stas823]

Try replugging all of the internals. I would also maybe try another kettle lead.

 

[WalderX]

Buy a cheap ~£20 PSU online or at local computer shop just to test if it is that? I think it is 90% likely to be that. Then you can RMA your XFX one once you have proved it, and keep the cheap one as a spare tester.

I would otherwise say faulty mobo but you say that once powered on it works completely normally so I can't believe it would be faulty mobo.

 

[FreeStream]

I had this issue before, turned out the 5V Standby was failing causing all sorts of USB and wake issues.

New PSU solved it.

 

[PhoenixSP]

unfortunately did a rebuild a few weeks ago with a new h100i so i doubt its a cable issue as it occurred before and after. Will try a different kettle lead though.

The issue with an rma is 80% of the time i turn on my pc it works perfectly with no signs of problems even playing resource intensive games so i fear i would just be wasting postage money trying to rma it.

I have found that pushing the plugs on a separate power strip causes my pc to make the disconnect noise and for a usb port to show up in windows as not working. This is strange as there is no physical link between each power strip other than they share the same electricity.

 

[BluD]

I had the same problem with and old monitor and my old power supply, was failing capacitors in both. Since your power supply is so new i can't see how that could happen though.

If ya can get ya hands on another psu i would test it, i wouldnt fancy sending back a PSU though postage was hefty last time i got a dodgey one come through on a build. Maybe the supplier will help with the postage i dunno.

 

[PhoenixSP]

Tried another kettle lead with no luck, bit the bullet and bought an EVGA G2 850W PSU as knowing my luck i would pay postage for an rma and it will work perfectly just to spite me. Thanks for the helpfull suggestions.