I just finished cleaning the cart's edge connector with rubbing alcohol solution, but it still isn't working. I've tried positioning it in all sorts of different ways but to no avail. I think half of the bottom of the cartridge shell has a very slight slant to it that might be causing the problem. Eventually, I should test the cart in my Coleco Adam computer just to see what happens.
Hate to re-open such an old thread (my first post, btw), but I just wanted to add that I have "Electric Adventure Classic" by Collectorvision Games that I just recently obtained off ebay. It also doesn't want to run (just absolute blackness on my TV screen). I have noticed some issues with the cartridge slot running other 1980s-era carts but ultimately, they do work most of the time. It's tricky dealing with these old game consoles and computers sometimes!