Sapphire 390 nitro high cpu usage in Idle and crash

Hi Guys

 

this story starts when I decided to change thermal pad and thermal paste to my 390, first time I changed only thermal paste but the temperature still was high, then using gpu-z I saw that the vrms were too high(about 70/75°) then I changed also thermal pad( using Arctic thermal pad with 1 mm thickness). During the second operation of thermal pad change, I saw little scratches on gpu(very little), ok I put the new pads on vrm and gpu memory and close the heatsink(and re change thermal paste).

Well, I installed gpu in the case and re installed driver, now begins problems. After few minutes of low gpu usage, using sapphire trixx programm, gpu usage increases up to 97% and the gpu

temperature increase in few seconds up to sistem crash. I tried to change settings from trixx, for example power supply up to 10% and seems work properly but after I launch Games gpu go in crash.

I cannot find the solution, I do not know if I have done physical damage to the gpu or is just a software problem, what's your advice?

 

Thank you