Guys, I found the solution!
First when my replace arrived I tried to connect the Riser Cable. This time, my PC boot up, but after 2 minutes of gaming, the problem reappered, my GPU crashed.
Forget about this “case PCI cover” (don’t know how it’s called), it’s only because my video card sucks and it curves so don’t touch PCI pins correctly.
So I decided to WRAP my riser cable with 1 layer of alluminium foil.
”HEY NOW EVERYTHING WORKS FINE!!!...........WAIT A SECOND, WHAT IS THIS HORIZONTAL LINE ON MY SCREEN?”
Well, I deduced was some interference with the Mother