tldr: I broke my 2 fans on GPU by cleaning them and ordered new ones (which will arive only in 2 weeks). First fan doesn't spin at all and second wiggles, but won't start spinning. I also noticed some strange behaviour of my GPU:
If I disconnect the the fans (what is left of them) from GPU and try to turn on the computer - screen stays black. I guess this is some kind of hardware protection from running it without fans - which is okay I guess.
If I connect the fans to GPU and boot into OS (doesn't matter which one - Linux, Windows or mac OS). GPU works fine until the temperature hits 70˚per Celsius (158 Fahrenheit) after that screen turns off and I am able to turn the PC off only by holding the power button. After that, it boots normally and everything repeats after heating up GPU to 70. Is it also some kind of protection or I damaged the GPU? This GPU could have handled up to 90 degrees per Celsius before all of this happened. Also this is definitely not the PSU issue - this is out of the question.
Update: I noticed that it could go higher than 70˚ if I heat it up slowly - watching a video for example, but it also turns off later. It seems like it can't handle quick increase in core and memory clocks - screen goes black immediately.
Question: So the question is will my GPU work normally when I replace the fans with new ones (they are identical) or there is something wrong with the GPU?
Is there also some kind of protection because fans are not spinning and PWM doesn't send any data to GPU?
I thought that GPU should heat up to max operating temperatures regardless fan conditions (94˚), but it seems that it is not the case...