Hitachi 42PD7200 Service Manual page 31

TV Sound
[Tuner PWB Circuit]
No sound of TV
Are waveforms at
pin 30,31 of
IN01(L,R)?
NO
Is waveforms at
pin 2 of IN01
(SIF)?
No
Is waveforms at
pin 22 of U101
(SIF)?
No
Check U101
42PD7200 (PW2)
Yes
Check PTV2 connector
or Video PWB
Yes
Yes
Check arpund
QN01,QN02
30
Is voltage at
pin 22 of IN01
("H")?
No
Does voltage at pin 22
of IN02 change for Low to
High?
No
How about base of
QK02?
No
Check I001 of
Formatter PWB
Yes
Check
around
IN01
Yes
Check
QK02,QK03
Yes
Check
QK02,QK03