-12v reads 13.7

[Modifyinc]

My Dell XPS 8920 Desktop PC, which is now just a year out of warranty, will not power on at all. No signs of life. Yet if I press the PSU diagnostic button on the PSU, the LED lights green, meaning the PSU should be fine. Using a PSU tester, everything shows fine except for the -12v. It reads 13.7v and keeps blinking and beeping, I assume because that is too high. Is this dangerous and could this be why the PC will not power on anymore?

 

Now when I test the PSU while still in the PC and pressing the Diagnostic button on the PSU, it does not light up anymore. Yet I can still remove it and test it with my PSU tester, but I still get the 13.7v on the -12v

[chartkor]

6 hours ago, Modifyinc said:

My Dell XPS 8920 Desktop PC, which is now just a year out of warranty, will not power on at all. No signs of life. Yet if I press the PSU diagnostic button on the PSU, the LED lights green, meaning the PSU should be fine. Using a PSU tester, everything shows fine except for the -12v. It reads 13.7v and keeps blinking and beeping, I assume because that is too high. Is this dangerous and could this be why the PC will not power on anymore?

 

Now when I test the PSU while still in the PC and pressing the Diagnostic button on the PSU, it does not light up anymore. Yet I can still remove it and test it with my PSU tester, but I still get the 13.7v on the -12v

Only reliable way of testing this is borrowing a power supply from a different unit. 

[Guest]

8 hours ago, Modifyinc said:

I still get the 13.7v on the -12v

Considering your Dell PSU doesn't even have a -12V lead... that's pretty intriguing.