Chiming in from another notebook model (ROG G703GX). After repasting, the computer ran for about 5 minutes, then abruptly blacked the screen, while still playing my music and at some point "screeched" and shut down abruptly. After turning it back on, it presented me with this exact issue. Green flickery lines everywhere, danger sign on device manager, etc. I forced a restart by forcefully shutting it down multiple times. 5/5 times the lines came back. These lines ARE a defective GPU, 100%. I still can't say for sure what it is/was, but I opened it back up, removed the heatsink and removed all the excess paste around the die that got on the little resistors/capacitors on the GPU chip (the green part) and put a (kapton, but any should do) tape all around the GPU die (on top of the capacitors) to isolate them further from the paste and also the aluminium heatsink that could maybe have touched them (or was so close that it conducted via thermal paste idk). After that I reassembled it, started it back up and...