LG 42LY770M, Service Manual

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Only for training and service purposes
3. Analog RF Video Trouble Shooting guide
Check RF Cable
Connection
Y
Check tuner 3.3V power L8901
Y
Check CPU LVDS output
Reconnection
N
Check IC2300
Replace IC101
N
N
Replace IC2300
N
Y
Check tuner 1.8V power L8903
Y
Check IC8900
N
Replace IC8900
N
Y
Check tuner 5V power L8906
Y
Check IC2304
N
Replace IC2304
N
Y
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,,,)
4. Digital RF Trouble Shooting guide
Check RF cable & signal
Check tuner 3.3V power L8901
Check tuner 1.8V power L8903
Check tuner 5V power L8906
Y
Check IIC Signal
TU8900 Pin#4, 12
Y
Check IF Signal
TU8900 Pin#6, 14
Y
Check X101
and application circuit
Check IC2300
Check IC8900
Check IC2304
Replace TU8900
Replace TU8900
N
N
N
Replace IC101
N
Replace IC2300
Replace IC8900
Replace IC2304
N
Y
Replace X101
Y
Y