A cautionary tale! I was setting up a Harmony 655 with my plasma television, dvd home cinema system and Sky+. The kit was only a couple of months old. It took some time to get to grips with the best way of selecting plasma and dvd input cycling. In the end I opted for Ikki's method of programming specific AV inputs to channels on the television. During this period I updated and changed the Harmony configuration many times. The DVD screen is difficult to see from the other side of the room and I pressed volume up several times when in fact the DVD system was set to the wrong input for the chosen activity. I must have got it up to full volume without realising it. Unfortunately using the Harmony Help button then changed the input to the correct one - and at some point I must have put full volume through the amp (which is separate to the DVD box). I didn't hear it - but it obviously blew the amp - and stopped working. Apparently this is known to occur with JVC systems. Now I don't blame Harmony for this - it is obviously a fault of the sound system. However I do believe that unfortunately my programming efforts caused it to happen. I have replaced the amp - and it works fine. I just thought others might like to be wary - keep an eye on the volume when setting up your remotes!