Please I have the following problems with my motherboards.
I have 4 (P4) motherboards.

One: It powers but it does not display, I have changed the processor, the memory and the VGA card but still the same fault.

Two: It powers but the processor does not get neither warm nor hot, I have also changed the memory, VGA and the processor but still the same fault.

Three: The processor gets very hot, if the board is being turned on it will display and it will turn off by itself.

Forth: It will display and when I tried to format it, it will load the operating system files but when it will restart it, it will give the following error
…… missing
…… press any key when ready

Fifth: The motherboard powers but both the processor and the power pack  fan do not roll when I press the power button, so I tried to use a screw driver to spark the power switch irons on the ,motherboard, it powers but it will not display.

Please all the IT GURU in the house please help.