Hi, I have a four switch wood trim Atari 2600 I rescued from a local flea market. The video cable and the power cable had been cut in two, so I replaced both of the cables and the system cleaned up nicely. I hooked it up for the first time and plugged in "Outlaw". The game started up and played fine. Then I tested 3 other games that I own. None of them worked. Sometimes the graphics would pop up for a second and then go away. Other times I would get nothing but a black screen with a few gray bars on it. I then borrowed "Ghostbusters" from a friend and it plays just fine. This led me to believe that the other cartridges needed cleaning, but after inspecting them they look really clean. Any suggestions around what might be causing this. Could it be the contacts on the system itself? If so how do you clean it?