My 500x had this problem , yes the junk switches Line 6 uses are bad and need replaced ,, mine after 6 months (3 of them ) And yes warranty covered the labor and parts but not the 40 dollars shipping to get it to the nearest service center, which of course cam out of my pocket just like the original 500 plus tax I paid for the Piece of &^% . BEing sold and replaced ASAP . Way to go Line 6 , My XT LIVE has had speakers dropped on it , people have fallen on it , miss used and abused ...has never missed a beat ,, my 500x has to be wrapped in bubble wrap , and carried like an egg. Very Disappointed.
