But its normal when the gpu its pluged to frezze the whole rig?

Hello I have a problem with a Amd 5700xt Asus ROG Strix  i have a rig with 5 5700xt i modded 4 of them and everything works fine but when i modded the 5700xt Asus ROG Strix  the card just bricked it didnt appear on the hive os again.
The problem is that i switch the bios button and the card restarted but by mistake i just flashed again the bad bios and now the card is completly bircked.When i the card is pluged the rig is forzen when i plug my monitor with internal graphics the screen is black and i cant perform any commands.(I cant even enter the motherboard bios)
I have the original bios saved but now i cant flash it
Please help me