Changhong Electric PT4216, Service Manual, Page: 38 / 62

38
Five
、
no sound or low sound volume
no sound or low
sound volume
check XP302
、
XP303 connection
of power amplifier
board ； sound box
connection line
check XP302 、
XP303 output signal
check TA2024
power 、 mute
control
check TA2024 input
signal
normal
check UOC3 output
signal
check UOC3 output coupling
circuit R219 、 R220 、 XP907
Yes
check and change
TA2024
normal
check UOC3 input
signal
check 20th,30th pin
SIF input
TV
check sound input
other source
check UOC3
power 、 clock 、
reset 、 bus
Yes
Yes
check TAD5-
C2F21RW output
SIF signal
check SIF filter
amplifier circuit
normal
check and change
TAD5-C2F21RW
abnormal
check and change
UOC3
normal
check signal
source
、
sound
jack
、
input
coupling circuit
no input