TCL LCD32E9A-MS91 AP Service Manual page 30

Test waveform of
Pin6/9/10/11 of u700 if
OK
Y N
Check the voltage of U700 and mute
speakers
if 3.3V/12V no voltage
or low voltage,check
relevant circuitry
Fig4.Picture OK, but No Sound
Picture Good,but No Sound
increase the volume and press the
mute key on remote control
test waveform of Pin27/28/29/30 of
U700 if OK
Y
Check the power supply
control circuitry if
regular
Check voltage of Pin23 of
U700 and Q700/Q701 and
relevant mute circuitry
N
test waveform of
Pin54/Pin55 of U300 if
regular
Y N
check the pin23/24
Replace
of U600 input if
U300
normal
N
check
Z600/Z601
Y
replace
U600