No Video at 133Mhz

Have a pc with a Soyo Motherboard SyK7v Dragon with with an AMD 1.6 processor. Machine has been work just fine for several months. Checked it the other morning and had the blue screen of death. Tried to re-boot and I could get no video.
The FSB has been set to 133Mhz. If I set the FSB to 100Mhz it works just fine. I have cleared the CMOS did not make any difference. I have changed out the Video card, it made no difference.

I have no video when the FSB is set to 133Mhz.
Any Ideas, will be sincerely appreciated.

Robert Payne