Today my NES, which I bought a while back off Half.com by Ebay, stopped working. It had been getting worse and worse over a period of days; it could have just worn out (it's obviously old), or it could be because of a certain game or because of something I did to the system. One thing I did was turn the system on and off 3 times the other day with no game in it. (There was a reason, but it would take a while to explain.) I didn't really think this would do any harm to it, and when I put a game in afterward, it worked.
Anyway, now whenever I put a game in, even one that used to consistently work, the screen either is blank (this happens most of the time), has random glitchy graphics on it, or once in a while has the game playing on it with completely messed up graphics. Could someone please give me some advice, and tell me if turning a system on and off without a game in it usually causes it to mess up?