so my colecovision doesn't work right.  All I get is a black screen with a white line that scrolls through it when turned on. Been sitting here for awhile. Should I sell it as is or get it repaired.  Anyone have recommendations? Is it worth repairing?  How much might it cost? Thanks 

The power switches on these are prone to getting dirty and causing problems. My first suggestion would be to repair/replace and retest.

Doesn't the RAM go bad in these things? That would definitely cause booting problems. The Colecovision has a BIOS too, doesn't it? That could be a factor too, depending on if it's in a discrete ROM or integrated into something else. I remember hearing the main PCB inside the Colecovision can crack, instant system killer there.

Perhaps most eloquent is anyone I've heard about the Colecovision is that it was poorly designed with subpar parts inside. They will all need refurbishing eventually.