Gigabyte does not want you downgrading, so as far as I know the only way to downgrade is to do what I did in my post above. You have to intentionally erase/corrupt the BIOS then use the older version of efiflash to flash a pre F4 version.
Anyway, you should be able to get F4 working correctly if you pull the battery out of the MB for a few minutes, replace it, boot back up, and immediately try to enter the BIOS setup to manually configure it.
Timing window to press DEL is still narrow and iffy. Try pressing DEL the instant you get an image on the display, right before the POST beep, if possible, and press it at moderate speed several times.
Originally Posted by kizwan
You probably need PS/2 keyboard.
Rather ironic advice since for the last six months this board has not acknowledged the existence of PS/2 keyboards during POST.
F4 finally does, but before this revision you could only enter setup with a USB keyboard.