Silforty Element

I bought my eclipse head unit a year or so back brand new online. used it in my other car with NO problems. but as soon as i stuck it in the CL, the CD player didn't play any music anymore. it plays am, fm and so on but not cd wise....i tried using other cd's to see if it was just that cd but same thing happens. it reads the title and seems like its playing, except theres no sound. Can anyone give some feedback as to whats wrong with the head unit? BTW, both my old car and CL has stock equipment, only replaced the head unit using a harness, not a hack job. i know if i call up eclipse, their just going to ask me about where i bought it and all that bs and not help me unless it was authorized dealer. please help