Cleaning GBA Corrosion

The Gameboy Advance came out quite a while ago, with the last game for it published by Nintendo coming out in 2006. It's probably been a while since you touched your Gameboy Advance, which means it may be in terrible danger if you left the batteries in. As the battery depletes, hydrogen gas builds up in it. This can create pressure that causes the battery to rupture and release its electrolyte, which is an alkaline substance (potassium hydroxide). This substance can corrode the battery terminals, causing them to not work. Worse, it can get into the motherboard and corrode the traces, which is a much more serious issue!

I unfortunately ran into this issue when I felt nostalgic and decided to play Pokemon Crystal. One of the battery contacts had severe buildup of corrosion, and I had to open up the GBA to see if it had reached the motherboard... and it had. There's a lot of information on cleaning up the GBA spread over the internet, so I wanted to put it all in one place for my own future reference and for anyone unlucky enough to have to deal with this.

As an aside, if this freaks you out, it is perfectly valid to send this to a professional to get fixed. I haven't tried that yet, but there are services like RetroSix where you can mail your GBA to a professional who will diagnose any issues (including any issues beyond corrosion!) and fix them. I am showing you this guide in case you want to do it cheaply, more quickly, or just fancy a DIY project.

Ingredients

You will need:

White distilled vinegar. What you get from the store is fine. Vinegar will react with the corrosive material. There is a common misconception on the internet that AA batteries leak 'battery acid', but this is false. Car batteries leak a sulfuric acid, but AA batteries do not, which is why vinegar can react with it!

90%+ Isopropyl Alcohol (Rubbing Alcohol. We need this to clean up the vinegar after it is applied. You don't want vinegar left on your board. 90% is better. 70% is passable, but it will have more water in it, so it will leave streaks, take more time to dry, and increase the probability of a short.

Cotton Swabs. You will need these to precisely target inside the motherboard.

Toothbrush. Use this to scrub off the corrosion after vinegar has been applied.

Three cups you will not drink from. Use one to store the vinegar and one to store the alcohol. The third one should be used to keep track of screwdrivers.

Paper towel. Lay your GBA on a paper towel.

Screwdrivers. You will need one small one that is philips head or flathead, and one that is three-sided.

Latex gloves. Optional, but will protect your hands. You don't want the corrosive material on your skin.

Instructions

Assess the battery damage

Remove the battery casing and look at the batteries. One of your batteries may be so swollen that you have a hard time getting it out with your hands. In my case, the battery was basically fused to the terminal so I couldn't budge it. With your gloved hands, you can try rotating it to loosen it up a little. If you have a safety pin, you can gently prod at the corrosive material to remove it. It will form a powder that you need to remove later. I used pliers to remove the swollen battery, but you can also use a flathead screwdriver, anything that gives you leverage.

Once you've disposed of the batteries, look closely at the terminals. Note which ones are messed up. The left-hand terminals are not connected to the motherboard, so if those are the only ones with corrosion, you may be in luck. The right-hand terminals are connected to the motherboard, and so corrosion there can enter and affect the motherboard. This is a worse situation.

Open the case

Use your screwdriver to remove the 5 three-point-star screws and the 1 philips head screw. Put these in a container to keep track of them. I like to put them in a little cup.

Gently open the rear part of the case. The side grips may come off; that's okay, just keep track of where they are. The same goes for the power switch.

Take a look at the motherboard. Is there any corrosion near the terminals? If you have corrosion near the right terminal, then it is likely you will have corrosion near the power switch. Also try to see if there is any corrosion under the motherboard, as this means you may need to disassemble the GBA further to flip it over.

Clean the corrosion

Dip your cotton swab in vinegar. You don't want it soaking wet, just moist. Tap it against the terminal. You will hear a crackling noise and see some bubbling - this is a sign of the vinegar reacting with the potassium hydroxide. It will not just disappear right away.

Use a different cotton swab and dip it in alcohol. Once again, not soaking wet, just moist. Tap it against the areas affected with vinegar. You will know that you have cleaned it enough if it does not smell like vinegar. Wait a few minutes for it dry, smell it to make sure you got all the vinegar. If it smells neutral, then you're good. If not, follow the scent to see where it comes from and apply more alcohol to the source of the vinegar.

Continue applying vinegar and cleaning with alcohol until the corrosion is gone. If the corrosion is bad, it will take a lot of application. Don't rush it... take your time. Cleaning it is not urgent - any damage that may have been done has already been done.

Use a paper towel to clean up the bits of corrosive powder that will fall off.

What do you do if you get a little over-zealous with your vinegar application? Quickly apply that alcohol! You can also gently dab with a paper towel to soak up the excess moisture.

Your GBA probably has no residual charge in it if you haven't touched it for years, so it is unlikely that you will have a short-circuit. Nevertheless, be careful if you are using 70% isopropyl alcohol, as it has more water.

Testing your Gameboy Advance

Once you have finished cleaning it, wait 24 hours for any alcohol to evaporate. Leave it out in the open on a paper towel, covered loosely by a paper towel if you're concerned about dust. Don't put it in a plastic container as you don't want to trap the moisture.

Once it has dried, reassamble your Gameboy Advance. Put in fresh AA batteries. Turn on your Gameboy Advance. If it works, congratulations! If not, turn it off. Disassemble it again and check closely to make sure you did not miss any corrosion - flip it over if you have not already. Continue cleaning if there is something you missed and try again. If it still does not work, you may need to have a professional check out your Gameboy Advance. It is possible that it can be fixed, but that it requires professional tools you are unlikely to have. It is also possible that it is too far gone. In any case, you would want someone to help you.