My Jakks / Namco 5-in-1 Plug and Play TV console has messed up video. Any ideas on how to fix/troubleshoot?

I have a Jakks / Namco 5-in-1 Plug and Play TV console. For reference, this is what it looks like:

When I start it up, the audio works fine, but the picture is messed up. This is the game select screen:

I can play games just fine, except for not being able to see them very well. The connection to my TV is a dual RCA cable (one audio, one video).

Any ideas on what might be wrong, or how to troubleshoot?