LG 47LN5700 / 47LN570T / 47LN570Y / 47LN5710 (CHASSIS:LB33B) Service Manual ▷ View online
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Contents of LCD TV Standard Repair Process
No.
Error symptom (High category)
Error symptom (Mid category)
Page
Remarks
1
A. Video error
No video/Normal audio
1
2
No video/No audio
2
3
Video error, video lag/stop, fail tunning
3, 4
4
Color error
5
5
Vertical/Horizontal bar, residual image, light
spot, external device color error
spot, external device color error
6
6
B. Power error
No power
7
7
Off when on, off while viewing, power auto
on/off
on/off
8
8
C. Audio error
No audio/Normal video
9
9
Wrecked audio/discontinuation/noise
10
10
D. Function error
No response in remote controller, key error,
recording error, memory error
recording error, memory error
11
11
External device recognition error
12
12
E. Noise
Circuit noise, mechanical noise
13
13
F. Exterior error
Exterior defect
14
14
G. Network error
Connection defect / Network speed low
15
First of all, Check whether there is SVC Bulletin in GCSC System for these model.
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Contents of LCD TV Standard Repair Process Detail Technical Manual
No.
Error symptom
Content
Page
Remarks
1
A. Video error_ No video/Normal audio
Check LCD back light with naked eye
A1
2
LED driver B+ 24V measuring method
A2
3
Check White Balance value
A3
4
Power Board voltage measuring method
A4
6
A. Video error_ No video/Video lag/stop
TUNER input signal strength checking method
A6
7
LCD-TV Version checking method
A7
9
A. Video error_Color error
LCD TV connection diagram
A8
10
Tuner Checking Part
A9
11
Check Link Cable (LVDS) reconnection
condition
condition
A10
A11
A11
A10 : 32/37/42/47/55
A11 : 32 AUO
A11 : 32 AUO
12
Adjustment Test pattern - ADJ Key
A12
13
A. Video error_Vertical/Horizontal bar,
residual image, light spot
residual image, light spot
LCD TV connection diagram
A8
14
Check Link Cable (LVDS) reconnection
condition
condition
A10
A11
A11
A10 : 32/37/42/47/55
A11 : 32 AUO
A11 : 32 AUO
15
Adjustment Test pattern - ADJ Key
A12
16
<Appendix>
Defected Type caused by T-Con/
Inverter/ Module
Defected Type caused by T-Con/
Inverter/ Module
Exchange T-Con Board (1)
A-1/5
17
Exchange T-Con Board (2)
A-2/5
18
Exchange LED driver Board (PSU)
A-3/5
55
” : driver board
Other : PSU
19
Exchange Module itself (1)
A-4/5
20
Exchange Module itself (2)
A-5/5
Continue to the next page
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Normal
audio
Y
N
Move to No
video/No audio
No video
Normal audio
Check Back Light
On with naked eye
On
Y
N
Check Power Board
12v,3.5v etc.
Normal
voltage
Y
N
Replace T-con Board
or module
And Adjust VCOM
Repair Power Board
or parts
Check Power Board 24v output
Normal
voltage
Y
Replace Inverter
or module
N
Repair Power
Board or parts
End
Always check & record S/W Version and White
Balance value before replacing the Main Board
Replace Main Board
Re-enter White Balance value
※
Precaution
Established
date
Standard Repair Process
Revised date
LCD TV
Error
symptom
A. Video error
No video/ Normal audio
☞A4
☞A1
☞A2
☞A28
☞A7 & A3
First of all, Check whether all of cables between board is inserted properly or not.
(Main B/D↔ Power B/D, LVDS Cable,Speaker Cable,IR B/D Cable,,,)
2012. 12 .06
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Normal
voltage?
Check various voltages
of Power Board
( 3.5V,12V,20V or 24V…)
No Video/
No audio
Check and
replace
MAIN B/D
Y
Replace Power
Board and repair
parts
N
End
Standard Repair Process
A. Video error
No video/ No audio
☞A4
Established
date
Revised date
LCD TV
Error
symptom
2012. 12 .06
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