Nalot

I started to run my Xbox on an old Dell flat-screen monitor with an adapter cable. Everything ran smooth for almost a month. This morning i went to turn the system on and the screen tells me its in power saver mode and i need to move the mouse or hit any key to exit power saver. Ive tried hooking up a usb mouse and keyboard to the Xbox doesn't solve the issue. plugged the Monitor into a regular computer port worked fine, but when i brought it back to see if i had exited power saver as soon as i put the Xbox cable in it went right back. The cable splits audio off as well and the audio also works fine. Has this happened to anyone else or does anyone know of a solution to the problem? Thanks for any help you can provide.