first, you do NOT need an O/S for the bios to appear on screen.
you could try to reset the bios via jumper.
also could try booting without any drives or peripherals connected.
if that doesnt help, try booting with just one stick of RAM (test with both, one at a time)
if you have another power supply around, try that.
if none of these options work, you could have a bad motherboard or ram (or CPU, but that would be rare)