Clean Master System Cartridge Contacts with Brasso

When a Master System cartridge’s contacts have gone black with tarnish, a quick wipe often won’t shift it. Brasso metal polish is very good at taking tarnish off metal, which makes it effective on edge connectors, as long as you know its downsides. Here I open up a well-travelled Sonic the Hedgehog cartridge and clean its contacts with Brasso and kitchen towel.

Opening the cartridge

Flip the cartridge over and remove the two screws with a 4.5mm Gamebit. Take it nice and easy: the screws are designed to cam out (slip), so the manufacturer could see from the missing black coating if someone had been inside. Don’t worry, there’s no warranty left to void.

Inside, there was a lot of build-up on the pins. Isopropyl alcohol would probably have been enough for this one, but I used Brasso so you can see it in action.

Opened Sega Master System Sonic the Hedgehog cartridge showing tarnished edge connector contacts — Plenty of build-up on the Sonic cartridge’s pins

Is Brasso safe on cartridge contacts?

It works, but bear two things in mind. First, Brasso cleans so effectively because it removes a slight layer of the metal itself, so it’s not something to use over and over. Second, it really does stink. Work quickly, because the chemicals in it are fairly harsh on metal, and get it off again as soon as the tarnish has gone.

Cleaning the contacts with Brasso

Give the bottle a good shake and put a little on the tip of a piece of kitchen towel. Dab it onto the contacts, let it sit for a moment, then wipe over them with the still-wet part of the towel. You can see the gunk coming off, along with some of the metal coating.

Applying Brasso metal polish on kitchen towel to the contacts of a Sega Master System cartridge — Brasso dabbed on with kitchen towel

Once the black marks are gone, take a dry piece of kitchen towel and buff the Brasso off as quickly as possible. Don’t worry too much about any track marks. The difference was obvious.

Master System cartridge contacts buffed clean after Brasso compared with the uncleaned side — Buffed clean, with the other side still to do

For comparison, I tried the filthy other side with plain dry kitchen towel first. A good rub took nothing off at all. Back to the Brasso, a quick clean and a buff, and that side came up nice and shiny too, despite being filthy to begin with.

Shiny clean edge connector contacts on a Sega Master System Sonic the Hedgehog cartridge after Brasso cleaning — Both sides clean and shiny

Reassembly and cleaning the shell

Clean your work area, and if you want to clean the case, it’s best done with the board out. The board only goes in one way: into the front of the case, over the staggered pins. Put the back on and refit the security screws finger tight only. You’re screwing into plastic and will strip the threads if you overtighten.

This Sonic had been around the block, so I gave the outside a wipe with one of my favourite things to use on retro plastics: window cleaner (the one with vinegar). It’s a mild solution, so you can go hog wild with it. You can use isopropyl alcohol on the outside, but it tends to show up scratches afterwards. For a nice shine on plastics, a silicone car dashboard cleaner works well.

Did it work?

The contacts went from black and filthy to clean and shiny on both sides, and the cartridge went back together with a cleaner shell, even if the scratches remain. Brasso does the job well on heavily tarnished contacts; just use it sparingly and quickly.

More from the Sega cartridge cleaning guides: How to Open and Clean a Sega Master System Cartridge, How to Open and Clean a Sega Game Gear Cartridge.

More Sega on the site: the quick Master System II composite mod and changing the save battery in a Mega Drive cartridge.