LG 42SL90QD-CA (CHASSIS:LC91L) Service Manual ▷ View online
* Detail EDID Options are below
ⓐ Product ID : 0001
ⓑ Serial No: Controlled on production line.
ⓒ Month, Year: Controlled on production line:
ex) Monthly : ‘09’ -> ‘09’
Year : ‘2006’ -> ‘10’
ⓓ Model Name(Hex):
ⓔ Checksum: Changeable by total EDID data.
ⓕ Vendor Specific(HDMI)
4.5. Bluetooth
When pressing Bluetooth key by new Service remote control
(MKJ39170828), display the below message
(in Power only Mode)
-> the name of Red Box is changeable. Check the searching
(MKJ39170828), display the below message
(in Power only Mode)
-> the name of Red Box is changeable. Check the searching
result
4.6. Outgoing condition Configuration
When pressing IN-STOP key by Service remote control, Red
LED are blinked alternatively. And then Automatically turn off.
(Must not AC power OFF during blinking)
LED are blinked alternatively. And then Automatically turn off.
(Must not AC power OFF during blinking)
Confirm whether is normal or not when between power
board’s ac block and GND is impacted on 1.5kV(dc) for on
second.
board’s ac block and GND is impacted on 1.5kV(dc) for on
second.
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MODEL
MODEL NAME(HEX)
all
00 00 00 FC 00 4C 47 20 54 56 0A 20 20 20 20 20 20 20
INPUT
MODEL NAME(HEX)
HDMI1
67 03 0C 00 10 00 B8 2D
HDMI2
67 03 0C 00 20 00 B8 2D
HDMI3
67 03 0C 00 30 00 B8 2D
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1. TV/CATV doesn’t display
TROUBLESHOOTING
2. DTV doesn’t display
Check the TP output data of TU1804
Can you see the normal signal?
NO
Could you measure voltage of TU1804 &
IIC lines?
Are they all normal?
NO
You should check power line
& IIC lines.
YES
You should replace Main Board.
YES
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
Could you measure voltage of IC1804 & IIC
lines?
Are they all normal?
NO
You should check power line
& IIC lines.
YES
Check TU1100.
Can you see the normal signal?
Check the output of TR(Q1102).
Can you see the normal waveform?
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
YES
NO
Could you measure voltage of TU1100 &
IIC lines?
Are they all normal?
YES
NO
You should check power line
& IIC lines.
YES
You should replace Main Board.
NO
You should decide to replace TR (Q1102) or not.
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
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3. CADTV doesn’t dispaly(Only CHINA)
Check the TP output data of TU1502
Can you see the normal signal?
NO
Could you measure voltage of TU1502 &
IIC lines?
Are they all normal?
NO
You should check power line
& IIC lines.
YES
You should replace Main Board.
YES
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
Could you measure voltage of IC1502 & IIC
lines?
Are they all normal?
NO
You should check power line
& IIC lines.
YES
4. Component1/2, AV doesn’t display
Check JK500, JK501, JK502
Can you see the normal waveform?
NO
JK500, JK501,JK502 may have problem.
Replace this Jack.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
YES
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6. HDMI doesn’t display
Check input connect JK600, JK601,
JK602,JK603
Can you see the normal waveform?
Check DDC communication
lines(IC600,IC601,IC602,IC603)
YES
YES
NO
JK600, JK601, JK602,JK603
may have problem. Replace this Jack.
NO
After checking the Power of this chip, you
should decide to replace this or not.
YES
Check HDCP communication lines(IC107)
NO
After checking the Power of this chip, you
should decide to replace this or not.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
Check the input/output data of HDMI
Switch (IC603) & DDC line
NO
After checking the Power of this chip, you
should decide to replace this or not.
YES
5. RGB PC doesn’t display
Check JK404 ,
Can you see the normal waveform?
NO
JK404
may have problem. Replace this Jack.
Check the output of Main IC(IC100).
Especially you should check
The H,V sync and clock.
Can you see the normal waveform?
YES
NO
After checking the Power of Main IC(IC100) you
should decide to replace Main IC or not.
This board has big problem because Main
IC(IC100) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Main Board or not.
YES
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