Best Answer RobJDean185 , 17 September 2017 - 07:29 PM
Good call - the important bit in that referenced thread is 'Stuck Key'. I disassembled the unit and found that someone had allowed a battery to leak but only cleaned out the battery compartment. Although all visible parts were completely clean and the keys all moved completely freely, there was a pool of slightly sticky liquid on the back of the keypad, the keypad ribbon cable to the motherboard and contamination on the rubber pressure pad. After cleaning that off with a decent cleaning solution, the entire unit works normally.
Thanks for the suggestion. I couldn't find a decent breakdown of the process for taking this item apart so I took some photos and I'll post those separately in case anyone else needs them.Go to the full post