I have a 2011 T770 with joystick controls. I just started occasionally (once or twice a day) getting a D3905 and/or a D3907 (Left Joystick not in neutral) codes. I can wiggle the joystick around and press the "Press to Operate" button again and it will clear up, sometimes takes a couple of times. Not sure if the calibration has somehow gotten knocked out or what? Looked at the manual and it said calibration required only if parts were removed or replaced. Is there something that I can clean or adjust or should I do a calibration from the manual? I hate to take it in, especially for something that I can handle without the having service computer.