That board requires you to manually set your CPU clock. See page 11 of yor manual for the clock settings per your CPU I suspect that all you have to do is set the FIDJP1 jumper to a lower setting use the JP1 jumper on page 10 to clear CMOS and the board will post. Then you can experiment with the best setting for your CPU.
Me and a freind just recently purchased the Syntax S746FX SiS Socket A ATX Motherboard. We both have different APG Video cards and we both get a no signal on our monitors when we put the video card in. Iv put my video card in a different computer and it works just find. Pleas help!!!