Place the black probe on a known ground point (like the battery connector ground or SIM slot shield).
Find a functioning component (usually a resistor) near the display connector that correlates to this line and run a jumper wire to the 1-4-7-* trace point, as shown in various repair videos 1.2.3 . 2. Keypad Row 2 (2-5-8-0) Not Working
The Nokia 105 (RM-908) remains a reliable and straightforward device. While its physical keypad is robust, it is not immune to failure. By understanding the common causes of keypad issues and following a methodical troubleshooting process, you can often resolve the problem yourself.
Disclaimer: Repairing mobile phones requires technical skill. Improper handling can cause permanent damage to the motherboard. If you'd like to narrow down the problem, tell me: are not working? Did the issue happen after water damage or a drop ?
Before performing hardware repairs, try these simpler solutions: nokia 105 rm 908 keypad ways
: If the keypad is acting erratically, try a hard reset by typing *#7370# on the home screen. Use the default security code 12345 when prompted.
For software-related keypad issues or standard usage, these codes and settings are essential: Nokia 105 (2023) User Guide - HMD
: Keypad issues are often caused by corrosion or physical damage to the delicate copper tracks on the PCB. If a specific row or column of keys fails, it indicates a break in a shared supply line.
: When one keypress triggers multiple characters or a phone shutdown. 3. Jumper Solutions and "Ways" Place the black probe on a known ground
Locate a working point on the same line (often a test point on the back of the board or a series resistor).
If your testing indicates the keypad matrix is physically fine, the issue may be at the component level.
⚠️ Soldering on a motherboard requires precision and proper tools (e.g., a temperature‑controlled soldering iron and fine tweezers). If you are not experienced, consider seeking professional help.
: Set your multimeter to Continuity/Buzzer mode . Place one probe on the non-working key's center or outer ring and the other on its corresponding resistor or IC pin. Keypad Row 2 (2-5-8-0) Not Working The Nokia
Comprehensive Guide to Nokia 105 (RM-908) Keypad Ways Repair
Trace the positive terminal track located just under the CPU shielding area.
and melt a tiny bead of solder onto the tip of the wire to strip away its protective insulation layer.
When none of the keys respond but the phone powers on, the problem usually stems from a shorted component or an internal CPU failure. Inspect the small resistors located directly above the keypad matrix. If these components are intact, the main processor requires re-balling or reflow processing with a hot air station. Hardware Repair Procedure
Find the break in the line by following the color-coded paths on a schematic diagram.