got an e machine pc which i need to clean out for a friend.Thought i could get my lcd screen to work on it but it says no video signal.The only difference between the two screens is one plugs into the mains and the other into the pc mains power supply.Would that be the reason it says no signal.

nah, no differnece between the two, except the monitor will power off when the pc powers off.

Has it got two video cards in it, the one you have plugged the monitor into may the onboard one and maybe disabled in the bios.

Just a thought.

Rich

You probably have the resolution / refresh rate set too high for the LCD. Lower the settings to 800X600 and work up.

What sort of video connector is it?

Boot into VGA mode...

If it uses a DVI connector then maybe its cos the pc is outputting an analog signal but the monitor is expecting digital (or vice versa). Not all DVI leads are the same.