원문 게시자: Geoff Morris ,
The problem lies with the ribbon cable between the keypad and display. It either works loose or corrodes slightly. Non invasive solution: Press the front hard between the 2 leftmost function keys at the top of the keypad while using the keypad. It's really awkward but it works. Invasive solution: This involves sliding a blunt flat tool (spatula?) into the side join of the case by feel and then using a thin knife to locate and cut the plastic pillars in the middle of the case. I am sorry this is not very detailed but I decided not to risk it myself and have since lost the link to the site that gave instructions. I hope knowing it is out there will help you to search and find it.