LG 55LS675H (CHASSIS:LA2AG) Service Manual ▷ View online
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TROUBLESHOOTING
1. Power-Up Boot Fail Trouble Shooting guide
Check P401 All
Voltage Level (3.5V, 12V, 24V)
Check power connector and
RL_ON signal OK ?
Replace Power board
Y
N
Y
Check IC5002
RESET and UPDATE pin
Check switch SW501, SW502
Y
N
Check X5000 Clock
32.768MHz
Check X5000 application circuit
or Replace X5000
Y
N
Check IC5002 IIC
communication state
Check IIC line or replace IC5002
N
Check IR input state of IC5002
57pin
Check IR board
N
Y
Re-download PTC Micom
Y
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2. No OSD Trouble Shooting guide
3. Analog RF Video Trouble shooting guide
Check LVDS Cable
Check LCD Module
Control board
Y
Replace Cable
N
Check P401 All
Voltage Level (5V, 12V, 24V)
Check power connector and
RL_ON(pin1) signal OK ?
Replace Power board
N
Y
Check Q409 output Voltage(12V)
Y
Check Q409 application circuit or
replace Q409
N
Check TU3001 Pin7(Video output)
Can you see the normal signal?
Check tuner 5V power L3000
YES
NO
Could you measure voltage of TU3001 & IIC lines?
Are they all normal?
Check Mstar LVDS output
NO
You should check power line
& IIC lines.
YES
You should replace TUNER.
NO
Check IC5000
YES
YES
Check tuner 3.3V power L3001
Replace L3001
NO
Replace IC5000
Replace L3000
YES
NO
Check tuner 1.2V power IC3000
2pin : 1.2V
Replace IC3000
NO
Check RF cable & signal
YES
NO
Replace Mstar(IC101)
or main board
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4. Digital RF Trouble shooting guide
5. AV Video Trouble shooting guide
Check RF Cable
Check IIC Signal
TU3001 #3, 4Pin
Check IIC line and level shifter circuit
Y
N
Check Tuner 5V Power
L3000
Check L3000
Y
N
Y
Check X201
and application circuit
Check IF Signal
TU3001 #10, 11 Pin
Check tuner application circuit or
replace tuner.
N
Y
Replace X201
N
Y
Replace IC101
Replace IC5000
N
Y
Replace L3000
Check JK1700
Can you see the normal waveform?
N
JK1700 may have problem. Replace this Jack.
Check the input of Mstar(IC101).
Measure waveform at C217 because it’s more easy to check.
Can you see the normal waveform?
Y
This board has big problem because Main chip (Mstar) have some troubles.
After checking thoroughly all path once again,
You should decide to replace Mstar or not.
Y
Check input signal format.
Is it supported?
Y
Check AC cable for damage
For damage or open conductor
Y
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6. HDMI Video Trouble shooting guide
Check JK800/JK801/JK802
Can you see the normal waveform?
N
JK800/JK801/JK802 may have problem. Replace this Jack.
This board has big problem because Main chip (Mstar) have some troubles.
After checking thoroughly all path once again, You should decide to replace Mstar or not.
Y
Check input signal format.
Is it supported?
Y
Check AC cable for damage
For damage or open conductor
Y
Y
Check HDCP key NVRAM(IC103)
Power & I2C signal
N
Replace the defective IC
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