No BIOS video display problem

Hi,

I managed to set up the P4304CR2LFKN by installing 2 XEON processors, populate all RAM slots for total of 256GB RAM and nvidia graphic card (installed in slot 1 PCI Gen3).  But when I boot up, with processor fans and system fans blowing well, no beeping sound but there is no display from the internal video or from the graphic card output.  Tried clearing BIOS but still no display.  Please help.  Let me know if I missed a step etc or what can be the likely problem.

Thanks in advance.