Recently acquired a Yamaha RX-V757 receiver that came with two RAV272 remote controls. The volume buttons on both remotes were non responsive. Couldn't figure it out. All the other buttons seem to work fine. Came across this article. https://www.ifixit.com/Guide/How+to+clean+Non-functoning+buttons+on+remote/9611 It sure took care of business! Wasn't too difficult getting the remotes apart. The circuits under the buttons did not look dirty when I checked them out, but a Q tip with some isopropyl got some dirty when swabbed across the them. Put back together and all worked just fine.