Newer BIOS chips have what is called a boot block sector. When flashing the BIOS this part is not flashed. Basically all it does is run the floppy drive, and if you are lucky you will also get basic video. I have re-flashed a "dead" BIOS with this. The MB was manufactured in 1998. The first attempt at flashing failed-nothing but beeps on restart. I downloaded the correct Bios update, made a new floppy to flash the BIOS and reran the flash program. There was nothing on the monitor, just a black screen, but I could hear the floppy drive being accessed. Follow the flash utility instructions and let it do its' thing. It took several long minutes, but it worked.
I'm providing this link below. Do not hold me or vistax64 responsible.
Wim's BIOS Page: BIOS Upgrades, Motherboard identification and more...
Finally, you can approach your manufacturer of your PC or bios to purchase a replacement.