Originally Posted by Augiedoggy18
If you disassembled the gun, check to make sure you re-connected the wires to the motor.
Going on what Augie says, when you re-connected, or your friend reconnected, the wires to the motor you have to be careful not to bend the connector back and forth too much while you're trying to push it onto the spade of the motor. Doing this will break the connection and it won't be visible under the heat shrink of the connector you are pushing on. I'm not saying that this is for sure the problem, I'm just relating a problem I had with mine that might have happened to yours.