Kenwood receiver, and the mic input problem

kenwood kr-7600 with no sound output. i plugged an elect. gtr. into the mic input that is for 'singing' along with a tape. then, i played for a bit. i took it out, and stopped using that function. i turned off the unit. now i can get no sound from either channel. the lights are on and it seems to be functioning am/fm, etc. just no sound output thru speakers. checked spkrs, etc.