Question RX 580 overheating in booting process

Mar 17, 2021
Good evening everyone,
I come to you in a time of great need. I am a casual player with a pretty basic rig; but lately it seems like my R580X doesn´t like me anymore and since the cryptos are running wild I am not able to upragde my GPU anytime soon.

My Problem:
My Radeon RX 580 is instantly heating up after booting. I reach the desktop and After 10-20 secs my video signal is killed Due to the heat I guess. After fiddling around I found the backend next to the power plug (the section where there are thermal pads adjusted under the top of the metal plate)is getting extremely hot, causing the GPU to shut down And the PC to loose video signal.

My Theory:
I suspect the heatsink not having sufficient contact or some failure of the thermal pads. It might even be the screws (But I am afraid to screw further against noticeable resistance).

Taken Measures:
Drivers are up to date.
The Fans are running when booting up
No Components in the System have been changed.
Fans and Heatsink cleaned; new ThermalPaste applied.

My System:
Win 10 64bit
A320 MH MB
Ryzen 3 Processor
20 GB DDR 4 Ram
500 W PSU SilverStonee ST50F-ES230 (I know, 600 W would be better, but this rig has been running flawless for 2 years)

Btw. I never overclocked or messed around with voltage setting.
Any help is appreciated. I am willing to take extreme steps since the warranty is over anyway and reusing my insanely loud old Nvidia 950 drives me up the wall.

Thank you very much :)