I have had a frustrating time over the last month where the track ball won't move to the RIGHT.
So as a last resort I gently removed the Trackball assembly from the front of the keypad.
Disassembled the trackball assembly to find it totally full of dust and fluff obviously from pocket of shirt.
Cleaned and reassembled.
All good again.
Allow at least half an hour and plenty of patience with the little magnetic rollors.