Electronic – Clean/repair/replace the carbon pill of a rubber keypad

keypadrepair

I have several devices (calculators, remote controllers, …) with rubber keypads where some keys are dysfunctioning. As I understand it, this is because of the carbon pill since things work fine if I use something in metal to make an electric contact…

Is there any way to repair this at home? In the past, I tried to clean the carbon pill with alcohol, with no significant success. So is there a known-good way to clean, repair or replace the carbon pill?

EDIT: Here is a photo of the rubber keypad:
rubber keypad

Best Answer

I use household aluminium foil. With round punches or using a knife or scissors i make small alu-patches to cover the 'rubber' keypads.punched or cut alu-pads To stick the alu-pathes on the conductive silicone pads use silicone glue (ordinary silicone sealant to bond glass will do. Other types of glue even super glue (cyanoacrylate) won't work on a silicone surface on the long run). Apply a smal (!) amount of the silicone glue on the pad with a small screwdriver and attach the alu-foil to the pad using tweezers. Finally press down the foil on the keypads and firm the edges over the pad (cover the pad with a sheet of paper and then press gently with a finger. Check if the foil is centered on and firm over the pad so that there are no sharp edges that can scratch the printed circuit on the board when the key is pressed. [a well centered and firm mounted alu-foil[2] [nine pads repaired[3]

Related Topic