Here' a full solution for Nokia 1280 keypad problem. If encountered keypad failure on nokia 1280 the solution below might help fix and solve the problem, for it shows the complete connection line paths of each particular on nokia 1280 keyboard matrix.
The iner and outer key connection were all highlighted for easy tracks or tracing and check up procedures.
Nokia 1280 Keypad Problem Solution - Jumper Ways
There is a keypad controller chip that is mounted at the middle of the Nokia 1280 PCB board. If this chip become faulty or damaged, will totally result to keypad failure or malfunction. You may need to rework or replace the keypad controller chip if each of the connection line paths were all both okay.