My monitor (Dell 15" flat screen LCD) is getting to the point that is does not come on when turned on. The on/off switch flight flickers and some light movement on the screen. I can tap on it and set it down a little hard on the desk and it will work. I have been into the monitor section of my computer etc and checked the trouble shooting sections. Is this the monitor itself or a card in the computer? Any help/advise would be appreciated. I don't want to run out and buy another monitor and have it do the same thing.