Audio Systems: 2001 chrysler sebring cd player, chrysler sebring, flash 1

Question
i am having problems with the 4 disc cd player.  i had ac work done and it has not worked since.  the 4 lights on the cd player all flash at the same time and then it starts to flash 1 and 2 together, then 3 and 4 together--going back and forth.  i can't even get it to go from the radio to cd mode.  was this caused by disconnecting the battery?  if so, do i need some type of code and where would i get it?  thanks!!

Answer
if you remove the battery on that car and there is cds inside the changer
next time it sees power the cd changer start from the begining and gets stuck
if you can remove the cd changer open it and remove the cd's  most of the times the unit works again good luck