Asus M3A-H/HDMI dead after bios update

You could try unplugging and clearing the CMOS; the second part probably involves shorting out two pins. See your MOTHERBOARD MANUAL.

That will change your settings to default, it will not change your BIOS version.

If it won't start after that I don't know if it can be fixed.

UPDATE:
Try just removing the power cable for a minute first before clearing the CMOS. I had a motherboard that wouldn't start and that worked.