There's probably not much need to try to convince you to clean your games if you collect retro systems and games. However, earlier this year I started getting back into it, and I quickly realized that the Q-tip and rubbing alcohol method I used as a kid just wasn't cutting it anymore.
Cartridge contacts have had 25+ years now to tarnish and get all kinds of gunk on them, and after wearing out my fingers and hundreds of q-tips they were STILL dirty. I took my quest online and began searching for better methods to clean the games, but I was shocked at what some people were recommending - some went as far as to promote the use of sandpaper on vintage electronics!
After searching high and low, I found the amazing method described on Classic Gaming Quarterly that solved all my woes. I'm only writing this post to share that guide with you and hopefully save some headaches, but I thought I'd also share some more pictures just so you can see how effective it can be.
For a good example, I recently picked up Zelda 2 on the NES. While the cartridge itself looked good, the contacts had certainly seen better days. Using a soft Staedtler eraser, I cleaned the left half of the board above in just a couple seconds. The great thing is, it only takes a few rubs of the eraser back and forth before the gunk comes right off. Here's a before and after of the dirty side above:
