Green and purple colors waving around the screen.

Console powers up, plays, has full color, correct sprites but there are these wavey colors that fall down the screen in a wavey pattern. I've cleaned the board, changed the cable and even used a coaxile cable. Strangely the game doesn't boot with the coaxial, but those same green and purple wavey colors are still present on the screen. The TV plays an Atari, and NES just fine without the wonky colors.

Not sure if it's an age thing or what. Any help?