Motherboard won't post

I have a gateway 980 server motherboard, Seagate cheetah hard drive, 1gb ram. Computer fires up, however I don't get a response from the monitor - dark screen. monitor works, as in shows "no signal" for several seconds after turned on. Preobebly something simple, however I am baffled - Anyone have a suggestion ?

Did this computer ever work? Did anything change between the last time it started successfully and now? Are there any beeps?
Check that the video card and memory are seated securely and that all the cables are attached securely to drives and the motherboard.

Thanks for the reply - bought the motherboard used - installed it in the chassis - jumped two pins on the start control plug and fired it right up. can hear the hard drive - cd-rom accepts the system disk - can hear it start to process the data - no beeps - has the little pot at the bottom of the board - tried pulling the ram cards hoping for beeps - no joy - disconnected everything hoping for a problem to disappear - to no avail - it is on it's way to the range for a 200 yard target - you can save it if there is something i have not tried thatworks - i'd be greatful