Since the normal left sound channel, ES3204, CH7201 works well, problem could be in the audio D/A circuit PCM1715U left sound channel within the relevant circuit and peripheral components. Because of the left channel {16}, {17}, {} to 18 feet function and right channel {13}, {12}, {11} foot, can adopt the method of contrast test. Find {11}, {12} feet voltage than 18 {}, {} 17 feet down, find out is {11}, {12} feet external electrolytic capacitor leakage caused by, after replacing the capacitor troubleshooting.NGDservice manual download site