Jensen VM9311TS wont play cd

i have a 01 dodge durango. my jensen vm9311ts shows that the cd is playing but there is no sound. i just hooked up my aftermarket subs and amp, you can hear the bass of the songs on the cd but nothing from the speakers. everything works fine with an ipod and on tuner. cd issue was the same before subs and amp were put in. i got the jensen from a friend and i saw the cd player working fine in his car. i dont get it. any suggestions????