LG SPM2 - Page 37

3-10
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Only for training and service purposes.
< MAIN board top view >
ONE POINT REPAIR GUIDE
NO SOUND
2-4. HDMI
2-4-1. Solution
Replace MAIN board.
2-4-2. How to troubleshoot (Countermeasure)
1) Please check HDMI_+1V8 of L812, HDMI_+3.6V of R842.
2) If HDMI_+1V8 or HDMI_+3.6V is abnormal, replace MAIN board.
3) If HDMI_+1V8 or HDMI_+3.6V is OK, check soldering status of HDMI jack (JK401 /JK402).
4) If soldering status is abnormal, replace MAIN board.
2-4-3. Service hint (Any picture / Remark)
VIN
EN
VFB
SW
VBST
GND
HDMI 1.8V
470mA
Vout=0.765 x { 1 + (R2/R3)}
R3 R2
80mA
Vout=0.55 x { 1 + (R1/R2)}
R2
R1
200mA
HDMI 3V6
C874
10V/0.1uF
C882
10V/0.1uF
C879
10V/0.1uF
C881
6.3V/22uF
C876
10V/10uF
C878
50V/0.01uF
R830
33
R831
OPEN
R833
10K/F
R834
13.7K/F
R835
0
C841
10V/0.1uF
C840
10V/0.1uF
C843
10V/0.1uF
C851
10V/0.1uF
123
4
56
IC803
C847
10V/0.1uF
R836
47K
L811
2.2uH/3.8A
C848
6.3V/22uF
C846
10V/10uF
C844
10V/10uF
C842
50V/0.01uF
C845
50V/0.01uF
C850
50V/0.01uF
C852
16V/1uF
C855
6.3V/22uF
R832
OPEN
C873
50V/0.01uF
R848
47K
C849
6.3V/22uF
R846
10K
C883
10V/1uF
16
4
2
3
5
OUT
FB
GND EN
NC
IN
IC805
R844
56K/F
R847
10K/F
D809
B5819WBRE
R843
OPEN
C880
50V/0.01uF
R841
0
C853
10V/0.1uF
C854
16V/1uF
C885
10V/0.1uF
C884
50V/0.01uF
R842
0
L816
220ohm/2200mA
L817
220ohm/2200mA
L810
220ohm/2200mA
L812
220ohm/2200mA
C839
10V/10uF
C860
10V/10uF
DGND
HDMI_+1V8
DGND
HDMI_+3.6V
HDMI_PWR_CTRL








L812
L812
L817
L817