This machine boot image is normal, but no matter receive cable TV or AV input, there is no sound, adjust the volume and mute or not reflected, after the self-inspection screen shows everything is normal, but the fault is still. QjRservice manual download site
 QjRservice manual download site
The fault reasons of this are: QjRservice manual download site
 QjRservice manual download site
1 circuit, power amplifier (PA) 2 (H), D/A conversion circuit inspection process: QjRservice manual download site
 QjRservice manual download site
Suggest starting signal input circuit board H board maintenance, in a state with AV oscilloscope detect IC3200 23, 25 feet of a voice signal input, check IC3200 TV state in 62, 64 feet and a voice signal input, check IC3200 52, 54 feet have output. A preliminary judgment AV switch circuit is normal. Checked the voice processing circuit, first check IC2002 56, 57 foot a voice signal input, 27, 28 feet check IC2002 found no sound signal output, check the sound monitoring signal output IC2002 36, 37 feet also have no signal, preliminary judgment is IC2002 problem, in case of around one thousand check IC2002 including crystal oscillator circuit, power supply, etc. All is well. After replacing IC2002 sound image is normal.QjRservice manual download site