Oh youuuu~~ :3

1: Get a dry erase marker.
2: Cover the sharpie marks with dry erase marker.
3: Wipe off with a cloth after it sits for a couple seconds.
4: Repeat as necessary.

Is contact cleaner spray discouraged? I never see that as a suggestion. Could spraying it all up in the guts of the Gameboy cause problems?

Nope. Toothpaste.

Apply toothpaste to a cloth and rub it into the shell.

Try rubbing alcohol for the sharpie too, but this doesn't always completely remove it, especially upon textured plastic.

Will that remove sharpie? Because my gameboy is heavily doodled upon.

this makes me wish i still had a dishwasher. >:

another good trick for cleaning cases:  run them through a dishwasher cycle (top rack).

unless your washer has a heating thing on the top rack too, then probably not. 

it gets them squeaky.

I gave it about 20 minutes of scrubbing (on the metal contacts) with cuetips soaked in white vinegar.
Once everything was nice and wet, I scratched at the rust that had built up (because of the corrosion?) and then hit it with a bit more scrubbing and vinegar.
I kept testing it every 10 minutes or so and would get disappointed each time. Just as I was about to give up, that beautiful little red LED came on. I wish I could have recorded my face at that point, I feel like a king.
Then I went on to fix a few other gadgets that had similar problems and they work now too

For the sake of curiosity, what did you do to make it work? : P

It worked! I fixed it
This could the start of something beautiful, thank you!

Thanks Telerophon, I always see you around these parts and you're always helpful to everyone. I'm going to go find some white vinegar

That looks decent enough, but it's not as though I could tell you how or why it doesn't work from a picture.

There are a ton of good threads on basic DMG cleaning and maintenance, but in short:

• 91% Isopropyl Rubbing Alcohol is the best general cleaner for circuits and case parts. Lightly apply to oxidized contacts or grime to remove.

• White Vinegar dissolves corrosion (the green/blue circuit funk) in a chemical reaction. Lightly apply white vinegar with a damped cotton swab to corrosion on battery contacts or other surfaces to repair some intermittent connections.

• Use rubbing alcohol once more to clean switches and potentiometers: Use rubbing alcohol on a damped cotton swab to soak a few drops into sticky switches and scratchy potentiometers, then switch the switches or roll the potentiometers back and forth a couple dozen times. Let them dry out and see how they function.

Hopefully some of that helps. Good luck!

So I got this old dead game boy at a garage sale a few years ago for 5 bucks.
It doesn't work, and the battery compartment looks like this:

Do you think if I cleaned it with electrical contact cleaner or something similar to clean the corrosion, it might work again?
Obviously there's a stack of other things that could be the problem (and this is my first time so be gentle).

Another crappy internal shot:

Are there common things that tend to kill old DMGs (other then kids)?