GTX 770 games crashing?

I'm asking the question again in the hope of getting more answers.

When I bought a used GTX 770 from Gainword 2GB, all games crash after a short time. (even minecraft without shader) My power supply has 500 watts and with the power supply calculator from comfort it should be enough?

I've already done the following:

-Driver reinstalled

-Graphics card Downclocked

Windows reinstalled

Does anyone have a tip? Would be very grateful

The graphics card is eight years old. It may well be that it has its time behind it and is simply gone. You can monitor the temperature again, but I would guess a defect.

I did. The temperature is between 60-70 degrees. But it's still strange when I put the pc on again, minecraft ran smoothly at the beginning. When I finished installing everything again, it worked again. But I also think that the graphics card is just too worn out.