I have read several threads about same issue, but with each thread there are different solutions, I got confused. I have acer LCD screen connected to WinXP SP2 box, recently I experienced one of these message : 1- “ Input no supported ” . 2- “ No Signal ” and LED turns from green color to amber color. This happened while the PC is working (i.e. not on reboot) I thought the problem with LCD screen , I changed to other one , then same message appeared ( “ No Signal ” ).