PC Does Not Power On - No POST - No Fans - PSU Test Inconclusive

1adog1 · April 24, 2019

Hey everyone, I've got a bit of a weird one for you. I built this PC roughly 4 years ago, and for the most part it's been working great. Over the course of its life so far though it's had 5-6 occassions where after a full shutdown, it's refused to turn on again for a short while. The power button doesn't do anything to my knowledge, with no fans turning on and no POST happening. Usually after waiting for a few hours the PC powers on again normally.

After it happened again 2 weeks ago and I needed the PC quickly, I reseated the Motherboard PSU cable which fixed the issue. When it happened again today, a reseat did not work, and a PSU test using EVGA's tester produced mixed results. The first time the fan spun and turned off a couple seconds later, and following attempts resulted in the fan either not spinning at all, or again a couple seconds of fan spin before turning off.

While I'm pretty convinced the issue is with the PSU, what I'm not sure of is if this is just a MB cable that's become damaged (it was relatively tightly wrapped in cable management), or if the entire PSU is dead. I could also be misinterpreting an expected result and have a completely different issue, hence why I'm here.

SPECS

- MSI Z97 PC Mate MB

- EVGA 850G Supernova PSU

- EVGA GTX 970 SC GPU

- Intel i5-4460 CPU

- 16 GB DDR3 Corsair Vengeance RAM

- Corsair Carbide 500R Case

ELSknutson · April 24, 2019

ya it sounds like your PSU is dead

AlexWarFire · April 24, 2019

I would consider replacing the motherboard cable if you can, because if that's the problem, a cable is cheaper than a full on PSU.

1adog1 · April 24, 2019

Alright now I have some new information which might change things, while the fan on the PSU doesn't stay on, the PSU does successfully power a peripheral port (specifically a molex power plug).

1adog1 · April 25, 2019

And... after a few hours the system once again booted without issue, as if nothing had happened. I'm honestly at a loss, but to be on the safe side I've ordered a new PSU on the off chance the current one decides to take the PC with it the next time it goes <Knock on Wood>.