Monitor: hieroglyphics/line down middle

Last week, my trusty, year-old Dell PC monitor freaked after turning on my W2000, year-old PC. It showed a vertical line on one side and then the screen started filling up with hieroglyphics. I bought a new flat panel which worked fine until this weekend. Then, the same thing happened to it and now neither are working. Can you tell me what the deal is? Do I need a new video card or is it perhaps a power source problem?