I just wanted to add to this topic since this just happen to me at a show. I tried to switch my patch and nothing. This was a bad time for it to happen since I was going from soft to a heavy tone. Now the band is rocking out and I'm just there playing a soft sound. The switch still worked, but for some reason at that time it didn't change. The next day I took the back off of the 500x and unscrewed the circuit board where the switch are, and found two of the switches are not clicking. The switch that line 6 uses is common to have this problem over time of use. Fortunately fry's stocks the switch. So I removed the bad ones and replaced them, no more problem. Now I know stuff like this is not easy for everyone. I just wanted to put it out there if your foot switch isn't clicking when you step on it or push it with your hand. I bet you are having the same issue I was. I'll add a pic of the switch to show what it looks like. There is one place online you can order the whole switch assembly upper and lower and its plug and play. easy to replace. May have to remove some hot glue but not hard to replace. I found it for $17.99 at fullcompass part #50-02-0234. Hope this helps anyone else having this problem.
