Help! Low +12V, On-Off Restart Issues

[najirion]

Was just browsing a while ago when my PC suddenly restarts. To my surprise it went back on and nothing displays on screen. Checked the inside of my RIG to see the fans connected to the motherboard not working and I guess the entire motherboard is not working as well. Then it was restarting after a few second interval
What's going on!?!?!

This might be helpful
the +12V section reads 7.08V only.. X_______X
Is that normal or significantly low???
I don't remember that being like that.
Please help!
I'm using an ASUS P8Z77M-PRO
please see cpuid sig for specs

[cl-scott]

I would call that significantly low. +/- ~0.5V wouldn't be a big deal, but we're talking about -5V. First thing I'd suggest doing is putting in a new PSU, as that's the most likely culprit. If you're still getting the same issue with a new PSU, then it'd be time to RMA the board.

[HiVizMan]

That is hardware waiting to be damaged. Me I would not use that PSU on my system.

[najirion]

I was using this PSU (Corsair TX650) for 10 months now. I don't remember it being like this. So it's the PSU? I think somethings is wrong with it. This was just recent... I am getting screen freezes from time to time too

[cl-scott]

I was using this PSU (Corsair TX650) for 10 months now. I don't remember it being like this. So it's the PSU? I think somethings is wrong with it. This was just recent... I am getting screen freezes from time to time too

The PSU is the most likely source of the problem, but it is at least conceivable the motherboard is the problem. Still I'd say it's like 90% chance it's the PSU, 9% chance it's the motherboard, and a 1% chance it's something else.

[najirion]

Okay, thanks for all your help guys. Fortunately both the mobo and PSU is from one dealer and he's really easy to talk to. I think I'll just head there.. I'm really confused.. I installed a generic 500w PSU, same thing occurred but since it was an old backup I can't really make a clear conclusion

[najirion]

I had it checked, they spent the entire day checking everything and found that it was the motherboard
It was like the motherboard had a stroke, some of the headers aren't working and wasn't supplying enough power to the processor says the dealer's technician.
Anyway, It was still 6 months old, it was sent for RMA now.

[cl-scott]

I had it checked, they spent the entire day checking everything and found that it was the motherboard
It was like the motherboard had a stroke, some of the headers aren't working and wasn't supplying enough power to the processor says the dealer's technician.
Anyway, It was still 6 months old, it was sent for RMA now.

Well, the important thing is that you found what the issue was. I'm honestly a little surprised the unit would boot and run at all with just a bit over half the voltage it was expecting. Anyway, it might not be a bad idea to kind of stress test other components, like PCIe cards and RAM, when you get your replacement. Anything that would have been drawing power from the main 12V rail you will want to check. Hopefully everything comes out fine, but it's possible there's some collateral damage.

[najirion]

Well, the important thing is that you found what the issue was. I'm honestly a little surprised the unit would boot and run at all with just a bit over half the voltage it was expecting. Anyway, it might not be a bad idea to kind of stress test other components, like PCIe cards and RAM, when you get your replacement. Anything that would have been drawing power from the main 12V rail you will want to check. Hopefully everything comes out fine, but it's possible there's some collateral damage.

Thanks for the advise. Yep will do that. This was all of a sudden. Did OC my i5-2500k to 4.0Ghz with it and it was running fine. Even ran prime95 for 2 hours. Didn't restart or BSOD whatsoever.. wonder what happened to it..

[cl-scott]

Thanks for the advise. Yep will do that. This was all of a sudden. Did OC my i5-2500k to 4.0Ghz with it and it was running fine. Even ran prime95 for 2 hours. Didn't restart or BSOD whatsoever.. wonder what happened to it..

I'm no EE, but I'd say you suffered a capacitor failure or two. Some component, or components, that help regulate the voltage on the 12V rail failed. So you were probably getting some rather large fluctuations in the voltage coming down that line, hence why you want to make sure to test anything that gets power off that rail. Good news is, someone will probably be able to fix it when it gets back to an RMA center.