Check www.powerbookmedic.com
They have instructions on how to replace everything from your keys on your keyboard to your logic board. I've taken my computer apart a couple times with instructions from them and I highly recommend them.
You said he was cleaning the keyboard?
My F2 Key doesn't work anymore, but that's because I accidentally cut through one of the threads with a screw driver when replacing my keys after cleaning it. Pop the key off carefully and check to see if there's any damage on the threads around the area...