Toshiba Bios update crashed

I am in need of advice. My grandaughters L300 has been suffering from overheating, it has been cleaned but on looking for a fix for the problem found a bios update for it.
This what happened, the machine froze, then on restart it come up with a black screen and not bios boot. can this be recovered or is the chip blown. I tried to flash the bios by dropping the battery off the board, all we getting is black screen and light indicators. Short buying a new board is there a away of recovering this. Kind regards Dave.