Picture Ok, All Source No Sound - TCL L32B2800 Service Manual

Picture OK, all
source no sound
Check the voltage of
pin 3,13 of U602
Check the pin 6 of u602
Check the pin 7 of u602
Check the wave of PIN 4,12 of U602
Replace U602 or replace
the wire of speaker
Repair the 12v supply
Check q607,q608,q609
repair R691 and R692
check u601 and
volume control