My JR 9xII has been serving me well and is almost 6 years old. I found that the elevator channel now has a little offset at neutral so i needed a way to recalibrate the sticks. A search online found that 9xII has a service menu that allows stick calibration.
** FOLLOW THE FOLLOWING PROCEDURE AT YOUR OWN RISK **
1. Pull & Hold the spring loaded trainer switch into the forward position.
2. Pull AILE D/R switch up.
3. Power the set on while keeping ENT button on front panel pressed.
4. Rotate roller activator until Trim Step is highlighted.
5. Press roller activator on Trim Step, rotate to AILE.
6. Switch AILE D/R down, press roller activator, switch AILE D/R up, press roller activator.
7. Repeat Step 6 four more times and on the 5th (total) time access should be granted to the Service Menu.
Once in service menu, goto Stick Nut , center all sticks and sliders then click [STO]. Voila, no more elevator offset.
Some other functions of service menu can refer to here.