L7VMM2 trouble Re-booting

I have 2 L7VMM2 motherboards that wont RE-boot. No problem booting
from a dead start. Duron 1.3, 256 ddr memory, onboard audio/video 40
gig h/d.
Using Win Xp, a reboot just get a black screen and no post. A
ctrl/alt/del gets the same from dos with just a floppy hooked up.
Any body else have this board?
Any help welcome,
Thank you