LG 50PM4700 Service Manual page 42

4. Analog TV Video Trouble Shooting
Check RF Cable
Y
Check Tuner Power
(3.3V, 1.8V)
Y
Check CVBS Signal
TU1001 #8 Pin
Y
Check CVBS Signal
Q1002 Base
Y
Maybe BCM2112 (IC100)
has problems
Checking order
1. Check Tuner power (Pin #5, #7,#12,
#13)
2. Check Tuner I2C level (Pin #3, #4)
3. Check Video signal (Pin #8)
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Only for training and service purposes
Replace one of
N
L1108/L1109
& Recheck
N
Maybe Tuner(TU1002-1) has
problems
Replace one of
N
Q1002 Base
& Recheck
Pin #27
Pin #26
Q1002 Base
Pin #15 Pin #11
Pin #13 Pin #1
Pin #14
Pin No. Description
1 RF_S/W_CTL
2 RESET
3 SCL
4 SDA
5 3.3V
6 SIF
7 1.8V
8 CVBS
9 NC_1
10 NC_2
11 NC_3
12 3.3V
13 1.23V
14 NC_4
15 GND
16 ERROR
17 SYNC
18 VALID
19 MCLK
20 D0
21 D1
22 D2
23 D3
24 D4
25 D5
26 D6
27 D7
LGE Internal Use Only