908 Keypad Ways | Nokia 105 Rm

If a trace is broken between the connector and CPU:

While exact internal service manuals are proprietary, common RM-908 keypad ways can be identified by:

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. nokia 105 rm 908 keypad ways

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. If a trace is broken between the connector

First, identify the keypad connector on the motherboard (usually a small ZIF connector or soldered flex cable interface). On the RM-908, the connector is a 16-pin surface-mount component.

Here is the factory Keypad to CPU mapping: When a "way" is broken (due to a

| Pin No. | Signal Name | Goes To (Component) | Function | |---------|-------------|---------------------|-----------| | 1 | KBR0 (Column 0) | CPU (Row Sense) | Keys: 4, 5, 6, * | | 2 | KBR1 (Column 1) | CPU | Keys: 1, 2, 3, # | | 3 | KBR2 (Column 2) | CPU | Keys: Left, Up, Down, Right, Call | | 4 | KBR3 (Column 3) | CPU | Keys: End/Power, Cancel/Back | | 5 | KBT0 (Row 0) | CPU (Column Drive) | Keys: 1, 4, Left, End | | 6 | KBT1 (Row 1) | CPU | Keys: 2, 5, Up, Cancel | | 7 | KBT2 (Row 2) | CPU | Keys: 3, 6, Down | | 8 | KBT3 (Row 3) | CPU | Keys: *, #, Right, Power | | 9 | GND | Ground | Common ground | | 10 | GND | Ground | Common ground | | 11-16 | NC / LED+ | Not connected / Backlight | Keypad backlight anode |

(Note: Actual pin numbers may vary slightly depending on board revision; always test continuity with a multimeter before jumping.)