What I've done:
Upgrade a PC for an acquaintance.
I installed the new GTX 1060 and MX500. Installed a new windows on it, everything ran how it should.
Though the SSD performance when I ran benchmarks it was lower than expected (It was hooked up to SATA 3.0)

I read that there were some SATA improvements on a newer version of BIOS.
So I decided to flash to a new BIOS version, F6 to F15 on motherboard GA-B75M-D3H
https://www.gigabyte.com/Motherboard/GA-B75M-D3H-rev-12#support-dl-bios

The flash was "successful". I reboot, but it says to insert bootable device.
I go into BIOS and change op the bootorder so the SSD is in the top. F10 to save and exit
Bum! Now it's stuck in boot loop.

The Issue:
3-4 boot loops, then it enters BIOS, the only thing it says is GIGABYTE UEFI DUALBIOS in the top, which it shows for a few seconds, then it reboots and the same loop starts again.

I've tried to clear CMOS on the jumper
I've tried to remove the battery (15 minutes and then over the night)
I've tried this:
"Since its dualbios system you can force to kick the backup into place. You can restore the backup bios by flipping the power supply switch in the back to off position. Hold the power button at the front, and while holding flip power supply to on position. As the pc turns on, -in one-two seconds, flip the power supply to off again. Then turn on the power supply and the pc. bios will load overwrite the current bios,with the backup, and after that, you will not have a boot loop.?"

Will I've be able to save it?
Not the first time I've run into BIOS issues. But a CMOS clear have always been the save.
I've flashed BIOS on at least 30 systems (specially Ryzen systems)

This post was edited by ZwiX on Aug 6 2018 06:36am

Best to attempt to go to their support at this point?

I mean it's bootlooped not bricked... so that's good. BIOS recognizes the SSD? I would say just reinstall Windows on it.

Sorry I misread. So you don't get full bios anymore? That is indeed very odd... I'll do some googling later and see if I come up with anything.

This post was edited by Incendiary on Aug 6 2018 07:40am

Nope sadly it only shows "GIGABYTE UEFI DUALBIOS" for a few seconds. and then the same boot loop starts again.
Like the problem this guy has:

i dont know much about this, only updated a bios once.. but one thing i heard, is you probably want new windows install if u change mobo or update its bios..

so have u tried reinstalling windows to the ssd? (i guess thats not a option if u cant get into bios?)

u got into bios after the update, but it f'ed up when u set the ssd as boot drive? so can u get into bios when the ssd is not plugged in?

Updating BIOS does not require a new windows install.
The BIOS is totally bricked. So entering windows installed menu through USB drive is not possible.

I the same story with no SSD connected. Also tried removing the GPU and going directly through the iGPU.
It is on a BIOS level it's fucked.
If it was hardware issue I would get some beep codes. Depending on if short or long beeps and the amount, I would know which hardware is the issue.

well yea i know, i have a ssd with win10 that will boot on any pc i tryed, it just says something like "windows is installing new hardwave" and then it boots

but actually, this is something i heard years ago, so it might only be the case with older systems and older versions of windows.. anyway just thought it might be related as problem seem to begin when u set the ssd to bootdrive

Don't Gigabyte motherboards have dual BIOS chips?
I would check the motherboard manual, for info regarding that.

I think there is a switch or jumper on the motherboard, that has to do with this.

I'm not at all sure, mainly because I've never had a motherboard with two BIOS chips.
But I think I read somewhere that it can't use the 2nd BIOS chip without first changing a switch or jumper on the motherboard.

Like I said, I would check the motherboard manual for info regarding either the switches and jumpers on the mobo, or switches or jumpers regarding the dual BIOS chips.

tl;dw
short pin 1&2 from bios_M while computer is on, so it forces it to boot from 2nd bios

Good job.