All motherboards I've had my hands on have had a dip switch or jumper that lets you reset the BIOS. Usually you find the jumper on the board (it's in the manual), move it to another position then power on, power off, reset the jumper and the BIOS is back to the factory default.

It's pretty much essential when doing overclocking since a bad power setting can make the computer refuse to turn on.

Quote: Original post by Fiddler
You probably meant PCI card (ISA has been dead for over a decade). Also that's only helpful if it's the video BIOS that's destroyed, not the motherboard BIOS.

No, I meant ISA. There are actually new motherboards being made with ISA support today, albeit for mainly industry to allow ISA cards so they don't have to rebuild something that already did the job in the first place. I haven't seen one in a new PC for awhile though because its old tech, thats why I said "probably not".

I'm not sure if using jumpers or dip switches will help fix a corrupt BIOS, the BIOS needs to be reflashed. It might be a good idea to create an autoexec.bat file on your floppy boot disk to load the BIOS flash program to help with doing things blind.

There is an alternative way of fixing it, but it requires a spare motherboard. We did this once at the computer place where I worked.

We moved the BIOS flash chip and put one from a similar motherboard in. We then booted the machine into DOS, swapped BIOS chips again and flashed it. That did work, but it's quite a while back, and on top of that, quite risky as you're swapping flash chips with a running machine. Could burn out your mobo...

Why would you have to do a hot-swap? Why not flash the chip on the other machine and then install it to the affected machine?

Quote: Original post by capn_midnight
Why would you have to do a hot-swap? Why not flash the chip on the other machine and then install it to the affected machine?

How would you install the broken BIOS into the working machine? You'd have to boot with the working BIOS then do a hot-swap.

That said, some motherboards have logic to reflash the BIOS automatically if POST fails and a suitable BIOS image exists on a floppy/CD/USB stick.

Quote: Original post by capn_midnight
Why would you have to do a hot-swap? Why not flash the chip on the other machine and then install it to the affected machine?

That is a last resort only done when you have tried everything else.
From BIOS FAQ:
Q: What is a "Hot Flash"?
A: If the system still will not boot up and you happen to have another motherboard with the same chipset lying around you can boot up in DOS with the good BIOS, then pop the bad chip in (with the system running) and try to repeat the flash procedure. This procedure is known as a hot flash. This often works, but you risk corrupting both BIOS chips, damaging both motherboards and buying two new systems!