3090 FE Crashing

[Shadowwizard]

Hey first time poster just don't know where else to go, My 3090 FE has suddenly started crashing and I can't identify why. After around 10 minutes of gaming both my screens go black and the gpu's fans peg to 100%, I looked around online and saw that the most likely cause of this problem is memory overheating as my gpu temps in task manager were reading normal (around 64 celcius when gaming at 1440p) so I launched HWmonitor and watched my memory temps, They got up to around 100 celcius and then the crash happened. Looked around online and everywhere said the thermal pads needed replacing and the chip needed re-pasting so I watched a bunch of tutorials and got all the recomended pads and thermal paste, took it apart took the old pads off and cleaned the memory with isopropyl alcohol and applied the new pads. Did the same with the chip and closed it all up, booted up and temps were looking way better. I was now idling at around 28-29 celcius on the chip whereas idle before was around 40 celcius and the memory was down to idling at around 40 celcius and before it was idling around 60 so I thought great everything worked and I should be fine, Launched a game and was playing for about 10-15 minutes before the same crash happened again and after turning my pc off and letting it sit for a while and then turning it back on and letting it idle for a while my temps were exactly the same as before I repasted and replaced the thermal pads so i'm really at a loss as to how to fix this or if i just didn't actually make a difference repasting and re-padding the gpu. Any help would be greatly appreciated as I truly have no idea what to do and I live in the uk so there's not really any good pc stores I can take it to for them to look at or fix for me. Sorry for long post, Thanks.

[Skiiwee29]

I had nearly the same problem with my 3090FE until I ended up fully water cooling it. I used GPU-z to monitor my memory temps and would get crazy insane temps, but without crashing. Ended up having to use an FPS lock to keep temps down low enough to not cause it until I blocked it up. Conversely, if you can, try and put a fan blowing directly across the backplate as its the back chips that are the ones overheating, not the ones under the heatsink. Otherwise, your only option will likely be to keep it locked to a certain FPS limit or underclocked/undervolted. 

[Shadowwizard]

@Skiiwee29 Thank you, I'll definitely try undervolting/underclocking the card first as i've never water cooled a gpu ( or cpu for that matter ) and that sounds very daunting!