1) Check, if you are in the right input in the back and not in the Phono input
2) @ the inputs there is a little switch. It changes the RCA input to the digital input! Make sure, that it is chosen correctly! If you go by RCAs, it has to stand @ CD!
3) Check on top of the mixer that the switch is correct. It has to stand @ CD/Digital!
Hope, I can help.
Greez