Question Reapplied thermal paste, PC ran properly for an hour and then stopped, No POST or display ?

[SnowsSnow]

I decided to reapply thermal paste on my 3 month old build, which had been running fine up to this point. After reapplying the thermal paste and turning the system back on, everything seemed to work properly and nothing seemed out of the ordinary, CPU and GPUS temps were all normal. After about some time, maybe 15-20 minutes, I decided to run a graphically intensive game, it ran fine for a total of 1-2 minutes, then the display went pitch black, no input, no audio. i checked the HDMI port, all is fine. then I restarted my PC. Everything lights up properly, the fans spin, initially very fast and then slow down a bit but are still spinning. The motherboard, GPU, RAM, and CPU cooler RGB lights are on, but the system won’t post, as it completely cuts off as soon as press the power button a few moments after starting it.

While reapplying the thermal paste, some got on my motherboard, I used rubbing alcohol to remove it but I later found out I didn’t get all of it. The thermal paste is Corsair XTM50, which claims to be electrically non-conductive.

This is my first build, and I’m not that experienced, I also don’t have a PC speaker and can’t get one to listen for the beeps, please help me.

 

[rgd1101]

full system spec? include make and model of the psu
recheck pcie power cable?

 

[SnowsSnow]

full system spec? include make and model of the psu
recheck pcie power cable?

MP600 2TB NVME SSD
RMX650 Watt PSU
2X32GB Royal Z 3200mhz
Gigabyte Aorus x570 I Pro Wifi
NZXT Kraken Z63
Ryzen 3900XT
Gigabyte RTX 3090 Vision OC

P.S: I understand that the power supply is technically below the recommended wattage, it was purchased before the reveal of the Ampere GPUs and it ran fine after I got my card, I planned on replacing it in the future but I just got my card 2 weeks ago and didn’t get around to it.

I rebuilt the entire PC out of the case, making sure to reconnect every cable properly, the problem still persists.
When starting the system without the GPU connected, the Storage indicator on the front panel blinks, and the PC doesn’t turn off immediately after pressing the power button, connecting the GPU changes that, as the storage indicator light doesn’t blink at all with the GPU connected, and the PC shuts off immediately when pressing the power button.

 

[SnowsSnow]

Update: contrary to my expectations, the motherboard, CPU, and PSU were all fine, the GPU died.

 

[dudio]

Update: contrary to my expectations, the motherboard, CPU, and PSU were all fine, the GPU died.

I was very suspicious of the PSU, and still am as a matter of fact. It is possible the GPU is fine, and your PSU just can't handle it any more.

 

[SnowsSnow]

I was very suspicious of the PSU, and still am as a matter of fact. It is possible the GPU is fine, and your PSU just can't handle it any more.

I tried a different PSU and the problem persisted