I've had GPU's, risers and a motherboard fail.
Every GPU, Riser and PCIE slot it was connected to died. What caused it? No clue. It wasn't even mining at the time.. The entire system fried. The only things that survived were the SSD and PSU.
Scary. And it was only a 4 card 750w system.. it was a big $$$ loss.
holy cow! that is a bad news, you didnt investigate what was the cause of that thing? If you come up with the solution please share it with us so that we would be aware also. thank you man.