Analysis of repair: the subwoofer output to normal, explain properly the subwoofer signal path, main left and right speakers there is no sound, faults may appear on the main speakers left and right channel amplifier circuit.8MUservice manual download site
Power play DVD disc to test, touch IC203 (TDA8920BTH) heatsink, very hot to the touch, heat anomalies, and IC204 (TDA8920BTH) the heatsink is just warm, initially judge IC203 has been corrupted. Is powered off with 500-meter Rx1k IC203 power supply pins in the way forward and reverse resistance to ground, ① measured 12 feet of forward and reverse resistance of 0 ω, then remove the IC203, directly ① 0 Ohm resistance between the 12 foot, 21, 22, also was 0 ω resistor between the foot, stating that the amplifier IC is damaged. Put on new IC203 (TDA8920BTH), ① power again before measurement, 12 feet in the road for forward and reverse resistance and found still 0 ω, description other than the IC203 damage, peripheral IC components there short phenomenon. Next focus check ①, and 12 feet perimeter of components, respectively detection filtering capacitor C206 (102), C211 (102), and C215 (102), and C243 (104) are normal, last measurement C2006 (104), found has serious leakage, is on to short-circuit State, for with new of C2006 (104) Hou, measuring have ①, and 12 feet of on to pros and cons to resistance has normal. Again boot, main speaker around speakers still no voice, so measurement IC203 each powered feet of voltage, ③, and ⑩, and 14, and 23 feet measuring have for +28V, again measuring 17, and 20 feet voltage for -28V, and measuring ①, and 12 feet of voltage is for 0V, normal should for -28V, continues to forward check the voltage of entered end, measuring have limited flow resistance R247 (10 ω) end voltage for -28V, and another end for 0V, split Xia R247, with Rx1 block measurement resistance, Infinite resistance is measured in open circuit State, this resistor is blown lead to IC203 cannot be -28V voltage ① 12 feet power supply, swapped new R247 (10 ω), the boot everything works, troubleshooting.

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