Question PC fails to start, but sometimes does

[Kritorian]

Hello, yesterday my PC suddenly stopped booting normally, when i press the power button my pc turns on for a second, there is the red CPU light on de EZ-Debug of my motherboard, and i can hear the relay click in my PSU, before it turns itself off, after a few seconds this repeats endlessly, until the PC suddenly boots up and everything works fine.

The amount of times this happens varies every time i try to start it. sometimes its 3, sometimes its over 20
I have detailed below what I’ve done and what my parts are, the weirdest part of all is that when i tried starting the pc today without any case cables connected it started without problems twice, i left it off for a moment to put the case back together (leaving the cables disconnected) thinking i would have to replace the case, but when i then tried to start it again, the problem came back.

Any help would be very very appreciated.

So far I’ve;
- Reseated everything. CPU, GPU, PSU cables, case cables, RAM, cables to my SSD/HDD
- Started it without a Graphics card, no change
- Started it without RAM, no change
- Started it with a different RAM set, no change
- Started it with a different CPU, no change
- started it with just the motherboard, CPU, and PSU cables to these two connected, no change
- Updated the BIOS, no change
- Reset and changed CMOS battery, no change
- manually checked PSU cables for their voltage, all okay

PC parts ;
- MSI PRO Z690-P motherboard
- Intel I5-12600KF CPU
- Nvidia 1080 TI graphics card
- Corsair DDR4 Vengeance (2x16) RAM
- Gigabyte GP-P750GM PSU
- Fractal North case

 

[COLGeek]

Do you have access to another PSU to test with?

 

[Kritorian]

Do you have access to another PSU to test with?

I should have a 500W PSU laying around somewhere, I just hope that that is not too low of a wattage for the other parts, i shall give it a try!

 

[COLGeek]

You have a slight issue with only a 500w PSU. Your GPU would like 600w and your CPU lacks integrated video.

You can try it, but a stronger PSU would be better.

https://www.techpowerup.com/gpu-specs/geforce-gtx-1080-ti.c2877

 

[Kritorian]

You have a slight issue with only a 500w PSU. Your GPU would like 600w and your CPU lacks integrated video.

You can try it, but a stronger PSU would be better.

https://www.techpowerup.com/gpu-specs/geforce-gtx-1080-ti.c2877

Yeah, i upgraded my GPU when i upgraded my parts a few years ago,
Would it be an idea to remove the GPU, plug in that 500W PSU to see if the issue persists?
Because right now, with the GPU plugged in or removed, the issue persists, so i do not think the GPU is what is causing this problem

 

[COLGeek]

Removing the GPU means you have no video adapter. Your CPU lacks integrated video.

Do you have access to a lower power GPU as well?

 

[geofelt]

Sounds like a PSU problem.
Gigabyte has had problems with your unit:
https://www.gigabyte.com/Press/News/1930
Contact gigabyte for a replacement,.
Or, replace it with a stronger high quality psu regardless.
Your next upgrade is likely to be a stronger graphics card that would benefit from a more capable psu. One way to tell the quality of a psu is by the warranty. 7 years is ok, but 10 and 12 years gets you a good unit.