I've got a non-functional ps2 controller. Buttons don't work but when i open it up and test the contacts they work. However, most of the contacts for the buttons think they are either the X or O buttons (eg. meaning when i press either directions on the d-pad it functions as an X button)

I can probably narrow down it down to a circuit board problem though. As where i'm from its humid and hot, and i tend to leave my controllers out in the open, i noticed that the analog sticks became sticky (like the rubber melted). Some of this 'melted' rubber might have seeped into the circuit board, and onto the contacts for the buttons causing the pad to not work.
If i could get this 'melted' stuff of the board, i think i might be able to get the controller to work again.

Ideas anyone?

Now before anyone says "Why don't you buy a new one?", i will say that i could do that, but then that defeats the purpose of having this forum then.
Also, i don't want to keep having to buy new controllers everytime something like this happens.