Service manual

Page 24 of 64
4-3 Tuner board trouble shooting
NG
NG
NG
OK
NG
TA8851
OK
Check DC Power:
L530 ＝9V？
L35 ＝5V？
L902 ＝9V？
L34 ＝5V？
L38 ＝5V？
Check U45 and relevant circuit.
DC converter U905:9V-Æ8V
Check U901 and U902
relevant circuit.
U901/U902 power supply
＝5V?
U901/U902 I2C I/O signal
≈5V?
Check input/output at
U5(TA8851). (use
color-bar signal, and
check CVBS and Y/C
signal)
TV audio problem
Check P801 solder status
In TV mode:
Check the system of
Video and audio are
right?
Check R902/R908:
R902＝GND?
R908＝5V?
If it have input but no
output, replace the U5.
Take down the L530, and
check U5 Pin18 =5V?,if
not replace U5.
Repair it.
Check input/output at
U45(MSP3450G), and
check DACMR/DACML
signal in main-channel.
OK