LG 21FU7RL Service Manual page 16

8. SOUND PROCESSING SECTION
ANT.
11100
TUNER
TUNER : RF signal is feed to TUNER through Antenna. IF output from Tuner is then given to 1 CHIP IC.
1 CHIP IC : 1 CHIP IC processes the input IF. Demodulates Picture and sound information and gives analog R G B
output for Display and SPKL/R as audio output, this sound output is further Amplified and feed to speakers.
Sound Amp : Sound amps(LA42102L) is and Audio Amplifier it amplifies the output sound signal from
Surround ic(LC75024E) and feeds to speaker which generates Sound.
9. CPT DRIVE SECTION
CPT Board Circuit
The CPT-BOARD assembly is composed of discrete type RGB
Amplifier.
Amp- Gain is defined by Resistance of R917, R912,R923.
High Frequency compensation is made by inductance of L901,
capacitance of C907,C904 and C902.
DC level of emitter of Q901,Q902 and Q903 is defined by R908.
VIDEO PROCESSING
11500
SECTION
180V
16101
R,G,B Signal-IN
L902, L903, L904
R
ONE SIGNAL (R/G/B)
MISSING
G
B
16002
CPT CIRCUIT VCC / GND
1 Vcc 180V
5 GND
9V
Copyright©2008 LG Electronics.Inc. All right reserved.
Only for training and service purposes.
11500 12500
1 CHIP IC NICAM IC
(LV762XX) (LC75024E)
11700
16100
16101
180V
R
G
B
9V
16100
L901
L902
Q901
L903
R916
R915
Q902
C907
L904 R906
R905
C904
R908
D902
Sound Amp.
13602
LA42102L(10W*2))
R G B AMP CIRCUIT
L901
R917 R912
L902
Q901
Q903
L903
R916
R915
Q902
C907
L904 R906
R905
C904
R908
D902
CPT DRIVE
SECTION
16004
DISCHARGE
PROTECTION CIRCUIT
ONE SIGNAL R/G/B)
MISSING
NO PICTURE, CPT
Dead
R921
C902
R922
16005
Spot Killer CIRCUIT
C901, R902, D903
SPOT & TRAY
- 16 -
Speaker
R923
R921
C902
R922
>
>
CPT / e-GUN
>
17006
Heater Voltage
FR932
e-GUN Dead
e-GUN LIFE
DECREASE
LGE Internal Use Only