So my wife just acquired her childhood ColecoVision, and it's in really nice shape with the steering wheel, the super action controllers, tons of carts with overlays, you name it. When I turn it on, the screen displaying COLECOVISION loads just fine and is crystal clear with a modern A/V cable. However, any game I put into the cartridge slot just loads a black screen.
I know the games are good... I have another working Colecovision and I tested them in that machine. So my question for folks more skilled than myself is where do you start in diagnosing and fixing an issue like this? Can the cartridge slot go bad while everything else remains functional?
Most the tutorials I've seen for black screens just show that the system doesn't power on at all, but that is not the case here. I am a total amateur when it comes to these things... all I've ever done is replace capacitors in a Sega Master System. Any advice would be appreciated. If this issue is discussed elsewhere, I apologize for overlooking it.