So, my card is dead. I was at 2645MHz@1.41v fullpot, things went well so far...after warming up, drying, remounting and stuff, it booted up to OS, blackscreen happend and that was it. I tried to heat it up more, left it over the night, no signal. Still it was fun, first serious 3d for me and gpu full pot experience.
GL to everyone and safe flight to China