Clean/repair/replace the carbon pill of a rubber keypad
I use household aluminium foil.
With round punches or using a knife or scissors i make small alu-patches to cover the 'rubber' keypads.
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.
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