A pencil eraser is a well-known remedy in all kinds of circles. A friend brings me his crashy scratch-built computer. I take the lid off, use a pencil eraser

A pencil eraser is a well-known remedy in all kinds of circles. A friend brings me his crashy scratch-built computer. I take the lid off, use a pencil eraser on the DIMMs, and reassemble it. It's fine after that, minus a couple of atoms or so of gold plating thickness. As long as it's a good pencil eraser, anyway -- some leave a smeary mess. 25 years or so ago, I was reading that the cart socket on the Nintendo used repurposed regular card-edge parts; parts that were never meant to work at multiple angles. I don't know the validity of this, since I haven't yet restored either of the two NESs that I have here (both of which I should have sold -- even broken and dirty -- during the NES Mini craze). I've thus never had a good, stern look at that socket. (But back in the 1980s, between us young kids and our electronics-luddite dad and a phone call to Nintendo, isopropyl was the answer.)