When a keypad trace is broken due to a cracked PCB or a lifted CPU pin, you can bypass the damaged path by soldering a small “jumper” wire from the keypad contact to a viable test point or CPU pin. This is the core of repair.
Always rule out non-hardware or surface-level disruptions before scraping trace lines.
Enameled copper wire used to bridge broken motherboard traces.
Set your digital multimeter to (Beep sound setting). Place one probe on the inner pin of a non-working button.
Put the phone back together and test all keys. Conclusion nokia 105 rm 908 keypad ways
To fix keypad issues, you must trace the connection from the unresponsive button back to the main CPU/IC section. 1. Keypad Row 1 (1-4-7-*) Not Working
Use your multimeter to find where the voltage signal cuts off along the trace line.
⚠️ 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.
Use 0.1 mm enameled copper wire. Heat the tip of your soldering iron to roughly 350∘C350 raised to the composed with power C When a keypad trace is broken due to
for a specific set of keys that aren't working on your device?
Before concluding that a keypad malfunction is entirely caused by a hardware failure, rule out a frozen operating system or deep software glitch. How to Hard Reset the Nokia 105 RM-908
. If the screen reads OL (Open Loop), the trace is broken, confirming that a jumper wire is required. Nokia 105 RM-908 Keypad Traces and Jumper Connection Points
(Note: Actual pin numbers may vary slightly depending on board revision; always test continuity with a multimeter before jumping.) Enameled copper wire used to bridge broken motherboard
When you press a key, the metallic dome sheet temporarily shorts the inner and outer connections together, sending a unique signal to the main processor.
Solder one end of the wire to the source and the other to the non-functional button pad.
Place the motherboard under a microscope. Examine:
