I had one evening to do make a USB port for my cabinet, and here's how I did it.
I removed the coin mech out of the 4 player galaxy cab (pictured above), and replaced the metal plate with a piece of craft wood cut to size. I then cut a hole for a large credit button (where the coins used to go!), and another hole for a USB port (in the former coin return). Painted it (first coat). got my soldering iron and other stuff together and ready. painted another coat.
While that was drying I got a new USB female end (you can buy from a hobby electronics store), and fixed it
to a small piece of plain unflashed PCB by pushing the connections through some pre-drilled holes in the PCB (I got this idea from an xbox USB hack). I got my USB extension cable, hacked the female end off and
resoldered the wires to the new female end. Tested it with PC (OK). Screwed PCB & USB onto small piece of wood.
Painted third coat on face plate. Called girlfriend, went shopping.
Attached USB to faceplate (screwed wood to faceplate), fitted new faceplate to cabinet (paint just dry!).
Very Happy! Drank beer
