i did the same thing!!! copy the bios from the good bios and flash is over then uninstall all profiles of any kind you even may need to do clean install on the PC . I messed up two 470 one only had one bios , and all the numbers matched from the other card with two bios i flashed it to the ref card same brand or made by the same company both were RX 470 same dates , and it worked , windows didn't see it or saw it like yours i ended up doing a clean install on the PC to wipe any junk profiles the driver cleaner didn't remove. that worked it installed and both still work great . the fact the PC see it is good . if it didn't then it may be bad or gone up . use the command line to flash it so i found out the hard way. also make sure the bios dates match even if the number match it can still flash but not work i had that happen , I used a bios dated July for the same card that has bios date of AUG bad idea sense it had two bios i was lucky.
I'm not to keen on shorting Pins it does work but more risky then doing re flashes . or uninstall all drivers , GPU-Z, afterburner anything that stores a profile reboot then try atiflash that error maybe gone. had that happen to.