Bios viruses are pretty rare but they do exist. I have no seen one in quite a while and removing the cmos battery should clear anything that is there for the most part. If you can try booting to bios and getting the computer to load, than check if there is a bios update. If you can reflash the bios this should clear anything that is there. This also could be a problem with your power supply as well, as this will sometimes happen when turn the computer off incorrectly. If you have another known good power supply you should try that.