Multimeter is low block test samples have "luo, luo" sound, trumpet essentially normal. Boot test audio power amplifier block IC201 voltage (AN5265) each foot, found that in addition to the four feet voltage of 0 v, the other foot voltage are normal. AN52654 feet for volume control, and voltage is proportional to the size and the volume control foot. According to the volume key 4 feet voltage measurement has been to 0 v, visible, thas in the minimum position or in the mute state. 16 feet voltage measurement volume control CPU end, press the volume key output control voltage change is normal, when the volume tube voltage control Q1111e voltage also follow changes, and the noise tube Q1113c no change voltage of 0 v. Measuring Q1113b voltage was about 4 v voltage, no sound is caused by noise tube accused. And the 4 v voltage come from? This is to repair goal. 8LNservice manual download site
 8LNservice manual download site
CPU9 feet is noise output, when conversion channel outputs high level voltage, noise. Measuring CPU9 feet around 2 v voltage, and resistance in the appended drawings R1159 left is 4 v. When the machine TV/AV switch integrated block IC31106 feet for high electricity at ordinary times, by the internal electronic switch to cut off the audio output, low power and connect at ordinary times, the noise output. Release IC31106 feet after connected with the open circuit voltage measurement immediately reduced to 0 v, the voltage is still 6 foot 4 v, prove IC31106 circuit inside the foot damage. Because there is no the same model M51320P replacement, and only local damage, as an emergency treatment, just put the IC21106 feet with Q1113b line can be cut off.8LNservice manual download site