if you brick your RX480 (in my case ref one) with wrong bios flash so the system even doesn't start with the card in, the famous 1-8 method still works:
1. enable IGPU or other videocard as the first in bios, connect monitor to it
2, make sure the system starts correctly without rx480
3. turn off the system, insert "dead" rx480, connect 1 and 8 pins on its bios somehow (soldering, paperclip or whatever, I used a paperclip), power on
4. if the system turns on, go to windows or dos, disconnect 1 and 8 pins on rx480 bios, check if "atiflash -i" sees the card then reflash it with proper bios file. Otherwise check if 1 and 8 are properly connected at startup.
rx480_bios_restore.jpg 247k .jpg file