the Nokia X3-02 solution for not working Power/End key problem. This solution may help fix if the phone shows charging indication or charging icon when the battery charger is plug-in but failed or unable to turn it ON.
In Nokia X3-02 the power ON-OFF key aside from it is on the keypad flex matrix it is also connected to the keypad filter IC. The solution below shows the connection line paths of the power key, this is useful without changing the filter IC and this can be used by bypassing the power key connection from the filter IC.
Just refer to given solution below and trace the said power key line paths.
Just manage to apply a jumper wire on a spots where the said Nokia X3-02 power key connection. This may help without compromising to change the filter IC and or the keypad flex matrix.