I flashed my Sapphire RX 570 Nitro+ 8GB about a week ago and it was working fine and was the only card in my franken-rig. Yesterday though, I changed my PSU (from 600W to 650W) and added a second Sapphire RX 570 to my rig, which was running on the stock bios. Upon start up, the fans on both cards were spinning very fast, and eventually the fans and lights on the modded card stopped working and it's not powering up at all now, while the unmodded card is working perfectly fine. I also had the PSU plugged into a watt meter, and it didn't go above 250W, which makes sense since the cards weren't under load.

Some things I've tried to fix this:
1. Testing the PCI slot with another card (which worked), and putting the bricked GPU into another rig (which didn't work)
2. Running ati pixel patcher
3. Running "atiflash -f -p 1 stock.rom" to flash the card back to stock, but I get an error message saying "adapter not found"

I'm now looking into flipping the bios switch, but I'm not sure if there's something else I should try. A lot of people have mentioned flashing/reflashing the card, but I don't know how that would work considering the card won't power up at all, which is why I wasn't surprised I got the "adapter not found" message.

Does anyone have any suggestions before I try to RMA this thing? If I flip the bios switch and it works, is there any way for me to reflash the other bios back to stock? Any help is appreciated.