- First disconnect the risers from the MOBO.
- after turning on the rig go to BIOS and set primary display as IFGX
- turn off
- put 1 riser back
- turn on
- in windows go and download GPU-Z from techpowerup, read the memory type (GDDR5) who is the manufacturer
- find appropriate mod for the exact memory type
- what amd driver you are using? search for DDU uninstall and after cleaning download and install amd blockchain driver
- when your done flash with new mod using atiwinflash 2.77
- download and run atikmdag-patcher
- repeat the process with the other cards

PS: you should always do a backup of your GPU BIOS rom

hope this will help..