3. How to do it when the Lock LED does not light and no sound from the D03K?

A:  1. Please check whether the unit is powered.2. Please check that your audio equipment / TV is set to output stereo PCM signals to the D03K.  If Dolby, DTS or other multichannel format audio was being output, please change to stereo PCM and try again.
3. Please check whether the input selection switch at the bottom is set to the correct position corresponding to optical / coaxial input used, or change to another optical / coaxial cable and try again.
4. If the problem persists please contact your seller for aftermarket support.