MY 2011 5.0SC Autobiography. Just swapped out my CD changer for a new (to me) one because the original would identify any CD as "Invalid Format" whether they were a commercial CD of a home recorded one. Tried cleaning the lens and all that but nothing worked. So I just installed a new used one, and it does read all the CDs but each CD stops playing at almost the exact same time, somewhere between 51 and 55 seconds. Doesn't matter which CD is in which tray they all do it. Then once it happens you can't restart that particular CD on another track but can switch to another one in the carrier, and it will play the first track for about 55 seconds then it quits. Its not a loose connection and I can't see any reason why it would be as consistant as it is. I'll try cleaning the lens again, but since it does play I don't know what difference a partially dirty lens would make if it was dirty. Any ideas?