Hi, I am brand new to this hobby and was wondering if someone can answer a question for me. I have a earthquake 3.5, bought it used and has run great thus far. Was just playing with it today and my steering just stopped, not even making the noise when you turn the wheel on the receiver. Truck still powers up and runs, just can't turn it! I see a battery pack or a servo pack that may control the steering, do those eventually go bad and could that be my problem? Are they hard to change? I appreciate the help.