DOWNLOAD LG 42LH20FD (CHASSIS:LT91A) Service Manual ↓ Size: 4.29 MB | Pages: 75 in PDF or view online for FREE

Model
42LH20FD (CHASSIS:LT91A)
Pages
75
Size
4.29 MB
Type
PDF
Document
Service Manual
Brand
Device
TV / LCD
File
42lh20fd-chassis-lt91a.pdf
Date

LG 42LH20FD (CHASSIS:LT91A) Service Manual ▷ View online

Check Signal format
Is it supported?
Check the HDMI Cable
YES
YES
Replace MAIN B’D IC 100
Check the ADJUST MENU
EDID OK ?
YES
Download EDID
(Refer to Adjustment Spec)
NO
NO
Replace
MAIN B’D IC107 (HDCP KEY)
Making 
Revision 
2009. 2 . 1
16/34
LCD TV
Symptom
HDMI 1~3 All No Video Problem
HDMI1 – ALL MODELS
HDMI2 – Except for 19/22LH20**
HDMI3 – Except for 19/22LU40**, 19/22LU50**, 19/22LH20**
26~42LH2000
32~47LH3000/LH4000
Check Signal format
Is it supported?
Check the HDMI Cable
YES
YES
Replace MAIN B’D IC 100
MAIN B’D JACK Check
JK600 -> HDMI1
JK601 -> HDMI2
JK602 -> HDMI3
YES
※ This case is that HDMI Video doesn’t display at the some HDMI input, not all.
Making 
Revision 
2009. 2 . 1
17/34
LCD TV
Symptom
HDMI1 or 2 or 3 No Video 
Problem
HDMI1 – ALL MODELS
HDMI2 – Except for 19/22LH20**
HDMI3 – Except for 19/22LU40**, 19/22LU50**, 19/22LH20**
26~42LH2000
32~47LH3000/LH4000
Check The Speaker
Check Speaker Cable
YES
Check P700 Cable
YES
NO
Replace MAIN B’D IC 701
YES
MAIN B’D
L705 Pin #1
L704 Pin #2
PWM Signal ?
Replace Speaker
NO
Replace Speaker Cable
NO
CHECK MAIN B’D 
JK700 or JK701
YES
Replace MAIN B’D 
JK700 or JK701
NO
※ If headphone is connected, Speaker sound doesn’t work.
Replace MAIN B’D IC803
NO
YES
MAIN B’D
L700 = 1.8V
MAIN B’D
Check R720, R721, R722
Signal
YES
Replace MAIN B’D IC100
NO
Replace MAIN B’D IC701
NO
Making 
Revision 
2009. 2 . 1
18/34
LCD TV
Symptom
All Source no Audio Problem
26~42LH2000
32~47LH3000/LH4000
Digital TV Video OK ?
YES
Replace MAIN B’D IC 100
Making 
Revision 
2009. 2 . 1
19/34
LCD TV
Symptom
Digital TV No Audio Problem
26~42LH2000
32~47LH3000/LH4000
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