Cleaning GBA circuit board

Hey all, I picked up a "broke/repair" copy of Pokemon Leaf Green off eBay for part of a project, was expecting that the gold pin connectors were going to be corroded/rusted and that was the issue. However when I got it the pins looked okay and I popped it into my GBA and everything seemed to be working fine.

So I took the case apart and I can see what appears to be some corrosion or something on the first 5 pins on one of the chips (see linked picture http://imgur.com/lvPuPes )

This gunk appears to be between the pins so I am assuming just using isopropal alcohol and cotton swab will clean it up. But I'm bit curious what cased it, Leaf Green doesn't have a battery and the rest of the board looks to be in great condition.

Anyone have any idea?

 

Could have been something spilled on it. Really no telling for sure.

 

So I have rubbed at it with some isopropyl alcohol and it is cleaning it a bit but it is under the pins, I don't want to poke at them with anything.. Would it do any good/harm to soak the chip for a bit in some isopropyl?

 

You could get a fiberglass pen and go lightly on them and it will clean them without causing harm to anything else. You can even get one at radio shack (I got mine there long ago).
http://www.radioshack.com/pro-grade-abrasive-fiberglass-pen/2760039.html#.VHH__8k9VTM

 

I use electrical contact cleaner and a soft bristle toothbrush. The contact cleaner I use is by Max Professional.

 

Probably a spill or something, if it is still dead reflow the pins of the maskrom, more likely though one or more of the holes in the circuit board are corroded, you can fix that by using a lot of flux and solder to fill in the holes, try everything else first it is a tedious repair.