Reply to s4 Channel D Problem

Hello, Last weakend i use my s4 with a mic (i never do it) so i configured the settings to do it and all worked fine.
Now i'm trying to connect, (as i'm used to) my turntables chanel c works "ok", but channel D doesn't reacive any signal , just work the mic entrance and there is not mic connected, Please help i've tried even too reestar all values and settings but nothings seems to work...HELP