The garage door opener on my MS ceased working. The wall switch worked, so I figured the problem was in the Genie opener because re-syncing the MS failed to solve the problem. I called the service that installed the Genie Garage Door opener and he found that "all the codes had been used up." (Do not ask me to explain that.) He erased all existing codes and I was able to sync. If you need help on this, you may contact call HomeLink help at (800) 355-3515.