You may also have managed to get chips in somewhere more... vulnerable. Two years ago in our 2006 robot, someone was drilling a hole right above our RC in our shooter's mounting bracket. The robot went to the field before anyone got a chance to get the vacuum... and during the course of the match a small aluminum chip managed to work its way
underneath one of the LEDs in the top of the RC and into the protective plastic box that covers the top of the circuit board.
We later found out that the chip of aluminum soldered itself on with the initial arc when it hit the V+ and GND pins.
Moral of the story... always cover the RC and have a
small vacuum cleaner handy!
-q
p.s. Since it's already broken as it sits, you may choose to void the warranty (which does not apply in this case anyways) on your controller and remove the four screws on the bottom that hold the top plastic cover on to expose the middle part of the PC board. There, look for the National semiconductor regulator (big power mosfet looking thing with heatsink) and see if your chip is there. If not, look around and i'm sure you'll find a short somewhere. Let us know here if you have further problems.