There are few possibilties that may causing the problem. Most likely it has to do with your display card.You could verify or check the card status by swithing off the poer to the CPU or chasis and pushing the display card in just in case it came off the motherboard.Switch on the chasis power if the problem persists then move on to another plan. Secondly, you could remove the card and insert it in another PC.If the problem remains then it is confirmed that display card is the problem. Beside the display card, it could also be that your CPU(chais)power supply has "died". Verify this by pressing the power and take note if the lights are on or it goes off almost instaneously upond powering.You should also listen to unsual sounds coming out from the CPU unit. I strongly think your monitor problem is due to your display card. It should have "died". Perhaps it is time to change. Please take note that I am not responsible for any damage incurred while following my instruction to repair your PC as I am not a professional and have no professional traning pertaining to PC repair. Regards, Rai ( singapore)