Here's the Nokia 1508 solution for not working keypads or keypad failure problem. This solution may possibly help if the there are ceratain keys on device stop responding or working.
To fix keypad problem, you may first check and clean the keypad membrane and contact pads for possible corrosion and oxidation build ups. Each particular keys were connected into a group of one connection, so it means if there is only one or two keypad keys that doesn't work, there is a possibility that the problem may lies on an open or cut-off connection line paths. You may refer to the solution below for tracing a particular which doesn't work or respond.
To fix keypad problem, you may first check and clean the keypad membrane and contact pads for possible corrosion and oxidation build ups. Each particular keys were connected into a group of one connection, so it means if there is only one or two keypad keys that doesn't work, there is a possibility that the problem may lies on an open or cut-off connection line paths. You may refer to the solution below for tracing a particular which doesn't work or respond.
Nokia 1508 Keypad Malfunction Solution
You may just trace a not working key to other key which is associated or also connected to it. The inner core and outer core both have different group of connection.
Here's the keypad contact pads Inner and Outer core layer group of connection.
Note: this may differ or may not accurate to other 1508 units.
Inner Core:
Group A - soft left, send, 1, 4 ,7 and * keys
Group B - up, select, left and right keys
Group C- down, 2, 5, 8 and 0 keys
Group D, soft right, 3, 6, 9 and # keys
Outer core:
Group A - soft left, up and soft right keys
Group B - send , left and down keys
Group C - select, 1, 2 and 3 keys
Group D - right, 4, 5 and 6 keys
Group E- 7, 8 and 9 keys
Group F- *, 0 and # keys
All of the keys connection were connected directly to the CPU main IC, Some problems is also cause by a firmware or software interruption.
