LG 42PM4700 Service Manual page 40

3. Digital TV Video Trouble Shooting
Check RF Cable
Y
Check Tuner(TU1002-1 Power
(3.3V, 1.8V, 1.23V)
Y
Check IF Signal pin #10,11
Y
Maybe MTK2112(IC100)
has problems
Checking order
1. Check Tuner power (Pin #5, #7)
2. Check Tuner I2C level (Pin #3, #4)
3. Check Tuner IF Signal (Pin #10, #11)
4. Check Ts level (Pin #20, #21, #22, #23,
#24, #25, #26, #27)
5. Check Ts Signal
Copyright © 2012 LG Electronics Inc. All rights reserved.
Only for training and service purposes
N
Replace one of Bead
& Recheck
N
Maybe Tuner has problems
Pin #27
Pin #26
Pin #15 Pin #11
Pin #13 Pin #1
Pin #14
Pin No. Description
1 NC_1
2 RESET
3 SCL
4 SDA
5 3.3V
6 SIF
7 1.8V
8 CVBS
9 T/C_IF_AGC
10 T/C_DIF[P]
11 T/C_DIF[N]
12 NC_2
13 NC_3
14 NC_4
15 GND_1
16 ERROR
17 SYNC
18 VALID
19 MCLK
20 D0
21 D1
22 D2
23 D3
24 D4
25 D5
26 D6
27 D7
28 GND_2
29 GND_3
30 1.23V
31 S2_RESET
32 3.3V
33 S2_F22_OUTPUT
34 S2_SCL
35 S2_SDA
36 LNB
37 GND_4
LGE Internal Use Only