That Kawai R-100 vintage digital drummachine came in with dirty buttons. They worked temporarily, so customer wanted me to replace or clean. Since I have a bunch of tactiles laying around which I usually order from good electronic stores such as mouser, digikey, farnell, reichelt or conrad (eBay, if no other chance), I could replace them quickly. I noticed some UV discoloration, but since you cannot see a change I din’t use retrobrite here. I cleaned the potentiometer in my usual way and ordered some dust cover replacements from a college. Modification was already in here. Customer can plug in different chips for different sounds. Everthing tested ok. Customer liked the result. Like always I share my knowledge and pictures with you.