Permanently repairs rubber keypad buttons by replacing the conductive material.
Your keypad fails when the conductive pad wears out and silicone oils seep from the keypad. This gooey paste blocks electrical conductivity and stops the switch from working. Membrane keypads block the oil from reaching the circuit board and offer a new conductor that cannot break down like rubber conductors do.
Video is for a similar model phone
1) Laser cut 3M peel and stick membrane keypad Printed instructions On-line videos and email support
If you are comfortable opening your phone you can repair your own keypad
Remove the back housing and circuit board
Clean the keypad and circuit board with isopropyl alcohol