Black screen

Hi,

Iv just put a PC 2 getha with bits of some old 1's from school and have finally got all pieces however, when I turn it on (bearing in mind that the hardware is spread all over my desk with no case) the fans on the psu and cpu go fine, there is a green light on the hard drive and a red light on the corner of the MOBO saying standby underneath it. But the monitor does not show n e thing, just says "no signal" tried uther monitors same prob, tried diffo g card, tried diff psu and also tried cleaning ram etc. Any Ideas?

Thanks,
Joe