TI-99/4A Cartridge Lifespan

Assuming that TI didn't make their cartridges with EPROMs (which would be subject to bit-rot), I'd suspect the connectors on the cartridge are dirty & therefore not making good contact with the socket. Video cartridges with normal ROM chips on them are pretty much indestructable it seems, so I doubt that the cartridges are bad. Opinion varies on how to clean cartridge contacts, but the two most popular ways seem to be: 1) pencil eraser and 2) alcohol & cotton swab. I prefer the pencil eraser as long as I'm able to get at the contacts well enough with it. Just be sure you get off all the pencil eraser particles off the card and be sure you use a PINK eraser, not the abrasive white (pen ink) kind. You might also try using some canned air or something to clean the cartridge socket on the TI. They make video-game socket cleaning pads for like Nintendo machines that you could probably modify to work in the TI. I really can't remember how TI cartridges are constructed, so it may be a big pain in the arse to clean the buggers. *