Tools needed:
Steps:
Example:
Remove the back cover, battery, SIM, and memory card. Unscrew the 5 Torx T5 screws. Carefully separate the front chassis from the mid-frame. Detach the keypad flex cable from the motherboard connector. nokia 105 rm 908 keypad ways
In the Nokia 105 RM-908, the keypad lines often run through protective components (EMI filters) or directly to the CPU. If these filters get damaged due to voltage spikes or water, the keys stop working.
If specific keys remain dead after cleaning:
The Nokia 105 RM-908 uses a standard 5x4 or 4x4 matrix. Below is the typical logic mapping for this model. Note: Always verify with a multimeter in continuity mode as board revisions vary. Tools needed:
Rows (R1-R4) – Usually connect to IC pins via resistors. Columns (C1-C5) – Usually the input lines.
Typical Button to Matrix Mapping:
In mobile phone hardware terminology, "ways" refer to the conductive paths (traces) on the Printed Circuit Board (PCB) that carry electrical signals from the keypad buttons to the Baseband Processor (CPU) or Keyboard Controller. Steps:
For the Nokia 105 RM-908, the keypad is arranged in a matrix grid (Rows and Columns). Each button acts as a switch that connects a specific Row line to a specific Column line.
When a "way" is broken (due to a cracked PCB, corroded via, or lifted pad near the connector), the processor never receives the signal for that specific row or column, causing an entire line of buttons to fail.
