Evga z370 motherboard giving CPU 12v error led when 8 pin cable is plugged into it

IsItGreg

Commendable
Jul 31, 2016
16
0
1,510
I've tried several power supplies however I'm still getting the error led. When the CPU cable is plugged in the computer shuts down immediately (fans and stuff get power briefly) after it is powered on, however, when it is unplugged it seems to start normally except for an expected post code 'C'. I've swapped out the power supply for one working in a nearly identical computer and there seem to be no changes (both PSUs are work with the other system). Any suggestions? Thanks in advance.
 
Solution


Have you tested the motherboard and components outside the case?

If you changed things around but you get the same error then it looks like a faulty motherboard.


If you tried another PSU and the system works without issues then you found the culprit: Faulty PSU.
Could you post your system components?
 


Sorry about that, I meant that there was no change between the power supplies. Both of them are working properly however the motherboard still has an issue.
 


There is no debug code, the computer just shuts off entirely a half-second after the power button is pressed. There is a light on that says CPU 12v error.
 


CPU 12v. Error LED appears when there is a voltage failure from the 8-pin ATX CPU power cable.

You said that you try more than one PSU, so then is either the motherboard, 8-pin connector, CPU socket or the CPU itself.

Check the the CPU socket does not have any foreign objects (hair, dust particles) or bent pins.
Also check the 8-pin connector on the motherboard.


 


Everything looks fine, is it possible that it is an issue with the motherboard to CPU connection like bent pins or could it be a fried CPU?
 

If the CPU socket looks fine, then it could be a faulty motherboard or the CPU.

Reset CMOS and try with only the CPU and one stick of RAM.

 


I tried that already, just running with the bare minimum, but it still does the same thing.
 


Have you tested the motherboard and components outside the case?

If you changed things around but you get the same error then it looks like a faulty motherboard.
 
Solution


They don't work outside of the case either. I'm gonna take it to a computer parts store and get them tested. I'm gonna see if they can tell me what the issue is. Thanks for your help though.