Service Modes, Error Codes, and Fault Finding
EN 17
L04E AB
5.
5.8.6
Tuner and IF
No Picture
1.
Check that the Option settings are correct.
2.
If correct, check that supply voltages are there.
3.
If supply voltages are present, check whether picture is
present in AV.
4.
If picture is present in AV, check with the scope the Tuner
IF output signal by manual storage to a known channel.
5.
If IF output is present, Tuner is working fine. If no IF output,
I2C data lines may be open, check continuity of I2C lines.
If I2C lines are ok, Tuner may be defect, replaced Tuner.
6.
If Tuner IF is present and yet still no picture in RF mode, go
to Video Processing troubleshooting section.
No Picture, No Sound
Figure 5-13 Fault finding tree “No picture, no sound”
Picture Ok, No Sound
Figure 5-14 Fault finding tree “Picture ok, no sound”
Unable To Perform Tuning
Figure 5-15 Fault finding tree “Unable to perform tuning”
Check AGC
Voltage, pin 1
of tuner
No Picture,
No Sound,
Raster Ok
AGC voltage
changes with
different signal
strength
Check AGC
circuit section
No
Check tuning
supply voltage,
pin 9 of tuner
Yes
E_14480_062.eps
170204
Check
V
T
Supply
Section
>30V & <35V
Check supply
voltage, pin 7 of
tuner
5V
Check Power
Supply
No
Check Tuner
pin 4 & 5
I2C Bus
Yes
Ok
Replace Tuner
Check other
functional area
No
Yes
No
Picture Ok,
No Sound
Check IF output of
tuner, pin 11
CVBS
present?
Refer to fig.
"Power Supply:
Set not working"
No
Check SAW filter output
(pin 4&5)
EU/AP/CH (QSS)- 1001
NA/LA/AP INT - 1002
Yes
Output Ok?
Replace SAW
filter
No
Check other
functional area
Yes
E_14480_063.eps
170204
Enter SDM
check optionbyte 1
Check if tuner
Supply Voltage
pin 7
Enter SDM and change
to the appropriate byte
5V
Check Tuner
Supply Voltage
Yes
33V
Check Power
Supply
No
Check I2C at pin
4 & 5 and tuner
Check other
functional area
Ok
I2C
Check I2C
circuit
Not Ok
Tuner
Replace
Tuner
Not Ok
Incorrect
Correct
Yes
No
Unable to
perform tuning
Not Ok
Not Ok
E_14480_064.eps
170204
