Nokia E73 Full Keypad Problem Repair Solution

This solution can be used ro fix and repair Nokia E73 with a keypad problem that is not working or responding, due to wet or water damaged.

This following solution shows the entire connection of the Nokia E73 keypad circuit, which can be useful for easy and quick troubleshooting methods.

This first solution shows the entire keypad flex matrix of QWERTY and NAVIGATION keys connection line paths. With this solution you can easily manage to trace a particular keys which does not work or responds.
The inner and outer core of the keypads where highlighted into different colors, each of the same colors means that these particular keys were connected with each other.

Nokia E73 keypad Flex matrix connection - tracks jumper ways

This solution below covers for Keypad Filter IC troubleshooting. There are two keypad filter chips is being used or mounted on Nokia E73 PCB board. IF one of these keypad filter IC become faulty it will result to a massive  keypad failure. The keypad filter chips solder ball bumps is being highlighted with colors for deeper troubleshooting procedures especially when the device  suffered water damaged. You may easily trace each of the connection tracks to determine if all the line paths were all okay.

Nokia E73 keypad Filter IC jumper ways
nokia e73 keypad IC jumper ways

In replacing the keypad filter IC you may need to carefully ensure that all the solder ball bumps were not lifted or damaged. In most common cases these filter chips were only become damaged due to a short circuit, excessive electromagnetic interference and electrostatic discharge. You may need to replace these chips for ESD and EMI protection on the other circuit on the device.