Sorry to resurrect such an old post, but it seems someone else is finally having this exact problem - namely me.
I went to flash the BIOS today to update it from F3 to F7, hoping it would solve a bug where after shutting down and powering off, the system would magically restart without my asking it to. I thought maybe I had the 'state after loss of power' set to start it up but I definitely didn't, so I figured it was probably some sort of bug.
Anyway, after attempting to flash the BIOS through the EFI GUI Flash program accessed from within the BIOS, the newer version extracted to a FAT32 USB drive, my system now refuses to do... well, anything really. No video output, no system speaker beeps, no POST, nothing. Everything ramps up as if it's starting, but it looks like the BIOS is probably hooped. I'm using the integrated video and have tried both the VGA and DVI ports to see if I could get something, no luck.
I've tried the instructions earlier in this thread to clear the CMOS, hasn't made any difference. I'll try leaving it unplugged and without its battery overnight, but I'm not very optimistic. Additionally, from what I can tell this motherboard does NOT appear to be Dual-BIOS, so reverting to a 'backup' BIOS may not be possible. You'd think for how simple and cheap it must be these days they would at least include an untouchable, factory backup BIOS that would always allow you to revert to something that works instead of bricking your entire system... but maybe I'm just dreaming.
I guess what I'm wondering is whether there are any tricks out there I haven't tried yet that might work? If not, is there any hope? Or is this board now too old for Gigabyte to give two hoots about whether it gets fixed or not?