Each column line to keypad pad: series 220Ω resistor (R200–R203). Each row line to keypad pad: direct connection, but pull-up at CPU side.
Set your multimeter to Buzzer/Continuity mode . Test from the center point of a non-working key to the center point of another key in the same row/column to see if the track is continuous. Common Jumper Solutions: nokia 105 rm 908 keypad ways