I just got the top loader that I ordered off of E-bay today, but most of the games I have seem to work. The Mario Bros 3 that came with it and the Mario Bros 2 work right off the bat, but every other game I have to try repeatedly.
I've already tried cleaning the games several times, some work for the time, but if I turn the game off I get nothing but green screen. So could it be that the connector is dirty? Or would I have to open up the carts and clean them that way, which would give me an excuse to finally order the screw bit.
Luckily the seller has a "return if not satisfied" policy, so if anything I'll just send it back.