55GA7800-CB (CHASSIS:LC37G) - LG TV Service Manual (repair manual). Page 35

THERMAL

THE    SYMBOL MARK OF THIS SCHEMETIC DIAGRAM INCORPORATES
SPECIAL FEATURES IMPORTANT FOR PROTECTION FROM X-RADIATION.
FILRE AND ELECTRICAL SHOCK HAZARDS, WHEN SERVICING IF IS 
ESSENTIAL THAT ONLY MANUFATURES SPECFIED PARTS BE USED FOR
THE CRITICAL COMPONENTS IN THE    SYMBOL MARK OF THE SCHEMETIC.

SIGN1100135

SIGN1100136

SIGN1100137

SIGN1100138

SIGN1100139

SIGN1100140

SIGN1100142

SIGN1100143

I2C_SCL4

LNB_OUT

R6903
36K

1/16W
1%

LNB

C6904
0.1uF
50V

LNB

C6910
0.1uF
50V

LNB

D6903-*1

40V

LNB_SX34

D6904-*1

40V

LNB_SX34

+12V

C6905
10uF
25V

LNB

C6903

0.01uF

50V

LNB

C6906
10uF
25V

LNB

A_GND

C6907
10uF
25V

LNB

LNB_TX

R6901

33

LNB

D6900

LNB

A_GND

C6911

0.22uF

LNB

L6900

33UH

SP-7850_33

LNB

R6900
2.2K
1W

LNB

D6901

30V

MBR230LSFT1G

LNB

I2C_SDA4

C6909
10uF
25V

LNB

A_GND

C6908

0.1uF

LNB

D6904

40V

LNB_SMAB34

A_GND

A_GND

C6902

0.22uF

25V

LNB

D6903

40V

LNB_SMAB34

R6904

0

R6902

33

LNB

A_GND

C6912

0.1uF

LNB

D6902

30V

LNB

C6900
18pF

LNB

C6901
33pF

LNB

IC6900

A8303SESTR-T 

DEV_LNB_A8303

1

VCP

3

NC_1

7

SCL

9

ADD

10

TONECTRL

11

TCAP

12

ISET

13

VREG

14

GND

15

VIN

16

LX

17

GNDLX

18

NC_2

19

NC_3

20

BOOST

5

TDO

8

SDA

6

IRQ

4

TDI

2

LNB

21

[EP]GND

(Option:LNB)

DVB-S2 LNB Part Allegro

Input trace widths should be sized to conduct at least 3A

Ouput trace widths should be sized to conduct at least 2A

69

LNB

2011.11.21

Surge protectioin

close to Boost pin(#1)

Max 1.3A

2.4A

2A

close to VIN pin(#15)

3A

Close to Tuner

Caution!! need isolated GND