So, you looked (and cleaned) between the AT contact board and the strip with the white semi-conductive rectangles on it? Sounds to me like that's where the coffee is doing it's damage. I can't say if those two items can be separated and re-positioned easily or not, but noisevoid can advise on that point. If you attempt to clean that area, be careful with the semi conductive pads: I'm hesitant to recommend alcohol for that stuff, not knowing exactly what it is. I might even consider trying distilled water on a small spot to see how it cleans up. After all, you're not trying to remove oils, but coffee solids. Believe it or not, in some cases a little clear dish soap + clean water is the best stuff. Good rinsing & drying is of course necessary.
Schmultz in the felt shouldn't affect anything electrically, but it might affect the feel. It also might ooze into unwanted places later. You might want to remove it also for soapy washing.
If it
was creamed & sugared, I'd try to clean it all out, if I could.
& learn to drink it black, like a man.

But really, do let us know how you get along. We like to help with stuff like this.
