GPU repaste and changed thermal pads, able to use for hours then VGA light on mobo lit solid after restart, no POST

[nvsamson]

Hi! I got a second hand 3080 Gundam ROG, not used in mining, some corrosion in the fins. Seller repasted it March 2023, thermal pads wasn't changed. I was able to use it for 2+ weeks without any problems, temps around 81⁰C max on max cyberpunk game settings stable 55+fps, then I decided to check HWINFO, saw that the hot spot is around 105-108⁰C. Decided to take it to a tech to repaste gpu and change thermal pads. (For my peace of mind since it's a second hand unit). Tech used cryonaut (original, I checked) for gpu die, Deep cool for the pads with correct thickness. Tested it, furmark for about 5 mins, no problem. Max temp at 69⁰C. Upon going home played with cyberpunk again for about 4 hours max temp 74⁰C, hotspot around 85⁰C, no prob. Tweaked with undervolting. 0.7V on idle, 0.9+V while playing, no problem. Clicked on the windows logo on afterburner then restarted my pc. Then no post, error light stayed white on VGA. Then pc restarts.

 

Trouble shoot done: reseat all RAM, remove cmos battery, shorted for cmos reset also, cold boot (press power button 30 secs while psu off and unplugged), boot up with 1, 2, 4 RAMs, switched RAM places

 

Upon some reading online, it might have been the afterburner, so I borrowed a working 1660 super, pc boots, uninstalled the afterburner. But upon putting my 3080, same problem. No post, light on VGA. Tested gpu on another unit, same prob (no display), technician said it's already code AA meaning it should have display already but none. Will bring in to the tech again tom to open the gpu he repasted. (He's on a day off today, others doesn't want to open it)

 

What might be the prob?

 

Here's a link to the video

https://drive.google.com/file/d/1qbKDjpBgXEGI_Sc-8IUPFUOKyTuZCq2I/view?usp=drivesdk

 

Specs:

MSI B660 TOMAHAWK WIFI

32GB (8X4) Corsair Vengeance RGB RT

i5-12400F

3080 Rog Gundam (10gb)

750W MSI MPG A750GF

Edited September 5, 2023 by nvsamson
Added link to video

[leclod]

Troubleshooting with a non-F cpu would have been easier.

Weird case, don't want to be in your shoes.

That hotspot temp is assumed not reported (at least in my case)

Edited September 5, 2023 by leclod

[nvsamson]

Just now, leclod said:

Trobleshooting with a non-F cpu would have been easier

IKR, tried to save a few bucks since I have a dedicated gpu, then gpu became the problem.

[leclod]

When changing gpu, screen can stay black on the first boot.

You did take this into account ?

[nvsamson]

9 minutes ago, leclod said:

When changing gpu, screen can stay black on the first boot.

You did take this into account ?

Yes when I changed to the 1660, has a black screen saying changed cpu or memory something. Then booted just fine.