I found this thread while researching exactly the same problem. Intel DH61CR motherboard with old BIOS (0044) having no display with a new RX 570, despite being on UEFI boot etc.
Used express upgrade files to get to firmware 0048 then 0099 at which point the onboard ethernet stopped working!
After some searching I found the following page:
https://kb.stonegroup.co.uk/index.php?View=entry&EntryID=267
They have link to zip file with the 3 BIOS files and text file with the following:
"
IMPORTANT NOTE: Updating the system firmware is done so at your own risk. Incorrect use may render your system unusable and invalidate warranty.
Copy the following files to a bootable USB key.
BE0048.BIO
BE0099.BIO
BE0116.BIO
STEP 1:
Update system to 0048 using Express BIOS update.
To perform Express BIOS update, boot system as normal and during POST press F7.
On the following screen select the removable media where your BIOS is stored, navigate to the correct folder and choose the BIOS you wish to use.
Note: You may be prompted to allow or reject the BIOS update, choose to allow it with the relevant keystroke.
---------------------------------------------------------
STEP 2:
Update system to 0099 using Express BIOS update.
To perform Express BIOS update, boot system as normal and during POST press F7.
On the following screen select the removable media where your BIOS is stored, navigate to the correct folder and choose the BIOS you wish to use.
Note: You may be prompted to allow or reject the BIOS update, choose to allow it with the relevant keystroke.
---------------------------------------------------------
STEP 3:
Update system to 0116 using Express BIOS update.
To perform Express BIOS update, boot system as normal and during POST press F7.
On the following screen select the removable media where your BIOS is stored, navigate to the correct folder and choose the BIOS you wish to use.
Note: You may be prompted to allow or reject the BIOS update, choose to allow it with the relevant keystroke.
If this fails then....
Update system to 0116 using recovery BIOS method.
To perform a recovery BIOS flash, copy the required BIOS file to the root of a USB key (NOTE: Please ensure only BIOS file you wish to use is in the root directory).
Turn off the target system, remove the yellow BIOS config jumper, plug the USB drive into one of the rear ports and then power on the system.
The standard Intel splash screen should appear after a few seconds and then the BIOS update process will begin.
Once BIOS update is complete and the system has rebooted and successfully completed POST, power off the system, refit the yellow BIOS config jumper.
Note: You may be prompted to allow or reject the BIOS update, choose to allow it with the relevant keystroke.
---------------------------------------------------------"
We had to do the recovery BIOS method (as express upgrade file said incompatible legacy BIOS installed) by removing the jumper but it worked and the ethernet then worked again, and the RX 570 worked too.
While too late for the original posters I just wanted to put this out there in case it helps anyone else.
Best Regards,
Seb