Sony KDL-43W755C / KDL-43W756C / KDL-43W800C / KDL-43W805C / KDL-43W807C / KDL-43W808C / KDL-43W809C / KDL-50W755C / KDL-50W756C / KDL-50W800C / KDL-50W805C / KDL-50W807C / KDL-50W808C / KDL-50W809C / KDL-55W755C / KDL-55W756C / KDL-55W800C / KDL-55W805C / KDL Service Manual ▷ View online
29
Troubleshooting
3-2-6. LED BLINKING 7x (Temperature Error)
7-time blinking
B* Board
Yes
Panel
NG
Change B* Board,
and Aging a few
hours
Setting
circumstance is OK?
Temperature,
Ventilation, etc.
Set to another
location, etc.
No
Symptom
improvement
Check I2C_C bus
communication OK?
Yes
No
Temp sensor
IC1401
I2C_C bus dumping or
Muffin check
Board Name
Board PWB (A side)
Detail
BMX
(IC1401)
Troubleshooting Reference
IC1401
30
Troubleshooting
3-3. No Sound
No Sound
Change the Speaker
Harness
Speaker Harness
NG
No problem
NG
NG
Check the UI
“
Speakers” setting
In “
AV Set-up”
Change to
“TV Speakers”
“Audio System”
“TV Speakers”
Symptom
improvement
Symptom
improvement
improvement
No Sound: Audio
No Sound: Tuner
No Sound: HDMI
B* Board
Speaker impedance
~ 8ohm (+-1.2ohm) ?
Replace
the B* Board
NG
Replace speaker
31
Troubleshooting
No
Checking Item
OK
NG
1
Check fuse F7751
Fuse short
Fuse open
2
Check connectivity audio Vcc to GND
C7862 – GND
C7864 – GND
C7866 – GND
No short to GND
Either 1 short to GND
3
Check connectivity audio +3.3V_MAIN to GND
(only for BMX board)
IC7751 (Pin5) at R7879 – GND
No short to GND
Either 1 short to GND
4
Check connectivity audio output to GND.
CN7751
Pin 1 – GND
Pin 2 – GND
Pin 3 – GND
Pin 4 – GND
No short to GND
Either 1 of pin short to GND
5
Check connectivity audio output path
(only for BMX
board):
L7751 (near to IC side) – CN7751 Pin4
L7752 (near to IC side) – CN7751 Pin3
L7753 (near to IC side) – CN7751 Pin2
L7754 (near to IC side) – CN7751 Pin1
Must have good connection
(~0 Ω)
Open circuit.
3-3-2. Main Board Power Off Checking (for Main SP Lch & Rch) for BMX board only
32
Troubleshooting
BMX board Side A
Troubleshooting Reference
IC7751
F7751
L7751
L7752
L7753
L7754
C7767
C7768
C7769
C7770
R7877
C7862
C7864
C7866
R7879
CN7751
1 2 3 4
C
N
9000
9000
18
16
R7876
R7878
Reference A
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