Here is a procedure how to trouble the issue above.
1. If there is two processors install, after power on system to see any red LED indication on front chassis. 2. If yes, remove second processor and memory and power on system board to see it have any video display. If yes then check your CPU and memory test each processor and memory modules individual to see whether the issue relate to motherboard or processor. 3. If not then remove the memory and power on system board to see it give memory error beep code. If yes then check or try with different memory, if no beep code then check motherboard may had ground issue when it install onto chassis.