Greetings
I have 7, yes seven Vtech 2420 cordless phones handsets - of which 3 of them have developed bad keypads. This means that one or more of the buttons do not function unless you forcefully "jam" your finger into them. On one of the handsets, this happened rather suddenly.
I have taken one of the handsets apart (nothing to lose there), and seen these types of button before. The 'buttons" are on a rubber button sheet with a black "contact" on the back that presses down to a spot on the PCB and shorts interleaved traces on the board to activate the button. The contacts and the traces on the board are a jet black - I can't determine what material they are made of (carbon?). I've tried cleaning both with a solvent, but no matter what, it doesn't seem to either help, (or even hurt) the problem!
Anyone have any suggestions or insights? These are great phones, discontinued and even refurbished or used replacements are expensive. I'd like to fix them...
thanks, Mike