Try the audio source audio signal is applied to the amplifier input pin block IC2301 left channel appears normal voice, we can see no fault amplifier stage. Stepwise manner using the same inspection, when the audio signal is injected into the IC2001 28-foot sound distortion occurs, according to this phenomenon should determine the point of failure on the block in IC2306 op amp and external parts. Because of the failure of the left channel distorted sound than normal large, it is believed that the negative feedback is not normal. IC2306 9 feet for feedback pin, measuring 9 feet by resistor R2386 open. Replacement of normal.GgYservice manual download site