What to do with toaster-box NES systems, that seem to break down and not work so well? Start a game session by blowing out a cart's dust. Then, with that fog-the-windows breath, breathe into the cart's area you dusted out; careful though, as spitting saliva could bridge adjacent contacts. Turns out, that condensation actually helps bridge the electrical contacts in the cart to the ZIF socket! I'm thinking that, over time, your cart contacts will get more of that bioelectrical crap from your breath and, well, maybe better contact will occur even if you happened to forget to firstly-dust-then-condensate the cart's contacts. Respect that ZIF socket, or replace it if your current one seems broken, but still respect the new one you get. It's a fragile thing!
Or just do what I do and clean the oxidised copper off the contact pins (both the cartridge and the 72-pin connector of the NES.)
