Where does the shorting happen on a water-damaged keyboard?

This question is more about general knowledge-seeking than it is for practical advice about my situation.

I have a 17" Macbook Pro (mid 2009) with a water-damaged keyboard. One row of keys does nothing, and many of the other keys do something other than their intended function -- e.g. pressing "p" results in a semicolon.

So I know that cases like these involve one or more short-circuits, and I'm just curious where on the keyboard shorts like these are located. Are they spread out around the key matrix, or is there some central control device that gets fried?