No signal message on monitor with xbox

[gabgab]

I am trying to hook an XBox 360 to a Gateway computer monitor. The XBox unit turns on, but I am getting a "no signal" message on the monitor screen. It worked originally for about an hour, then after turning it all off, would not come back on.

 

[hairystuff]

connect it to a tv with composite then configure it for component or vga and reconnect to monitor.