Guys you lot are scaring me with this flashing BIOS's between brands so let me get this out there.
Do NOT flash your card with the BIOS from another vendor!
MSI, Gigabyte, ASUS all use DIFFERNET PCB's, Voltage controllers, VRM's...etc..etc..
Flashing either cards BIOS onto another WILL BRICK YOUR CARD, DO NOT DO IT.
I have flashed my reference Palit GTX970 to the Palit GTX970 Jet Stream card and it worked because my Palit reference card and the Palit Jet Stream cards have the SAME, IDENTICAL PCB.
So if the card who's BIOS you're thinking of flashing does not have an IDENTICAL PCB to your card then DO NOT flash the BIOS's.
Glad I got that off my chest.
The above is very good advice however if anyone is dumb enough to flash the wrong BIOS to their card, the process for de-bricking an Nvidia GPU is as follows:
1: Remove the bricked GPU
2: Either get your system running off the iGPU, or if you have a P67/X58/X79/X99 board then install another PCI/PEG GPU and run off that and make sure it's default in the motherboard BIOS.
3: Put the bricked GPU back in.
4: Make a bootable DOS USB drive, and copy Nvflash to it along with a copy of your original BIOS (at the time of writing the is no Maxwell ready DOS version of nvflash yet).
5: Reboot, flash the BIOS (of the bricked card!), then shut down.
6: Reboot, return all settings to previous and enjoy.