[apalrd]

How hot was the servo? The thing that comes instantly to my mind is that it overheated - we had a similar problem, but used rubber bands to solve it (we had the entire ball supported on an arm by the servo). Also, check the wiring. We *had* position control on our elevator, but the wire on the potentiometer keapt falling out. We disabled it in code for that competition, and have fixed it for the next one. If you decide to switch to a motor, you can use a potentiometer to get position control, basically a software servo (more on that if you want). Also, how are you controlling the servo? Buttons? Joystick axis? How much load is on the servo (how big is the arm?) And are you able to replicate the problem? Try running it repetitively and see how long it takes to fail. also, check for mechanical problems like the shaft not in all the way. Also, VEX motors and servos are known to act erratically when they only receive power, maybe the connector is only partially in or a wire is loose? Try coding a joystick axis directly to a servo or pot [pwm05 = PWM_in1; //right X] or [pwm05 = Get_Analog_Value(rc_ana_in01) /4; //First Pot to Servo] and see if it still acts strangely, possible because of a programming problem. How old is the servo, VEX servos and motors have little thin plastic gears that are known to break after a few years of competition. If you have spares (they come with the motors and servos; little white gears in a little plastic bag) you can try that if nothing else works. That's all I have.