Emerson EWL2005 User manual

SERVICE MANUAL
20″COLOR LCD TELEVISION
EWL2005

4-2 L3202DC
S-2
S-2
S-1
S-1
S-1
S-1
S-1
Fig. D1
[1] Rear Cabinet
Fig. D2
S-10
S-9
S-8
S-8
S-10
S-7
S-7
S-7
S-3
S-3
S-6
S-6
S-6 S-5
S-5
S-4
S-7
S-7
S-3 S-6
S-6
[5] LCD Main CBA & Liquid Crystal Panel Unit
[7] IR Sensor CBA
[4] Main CBA
[3] Inverter CBA
[2] Jack Holder
[6] Function CBA
[8] Speaker
[8] Speaker
[9] Front Cabinet

4-3 L3202DC
TV Cable Wiring Diagram
CN101ACN102A
CN802CN801
Function CBA
IR Sensor CBA
Inverter CBA
Main CBA
LCD Main
CBA Unit
To Speaker
To Speaker
CN103A
CN312
CN311
CN460
CN101B
CN102B
CN103B
CLN411
CN411
CN490 CN450
CN105
To Liquid Crystal Panel
To Liquid Crystal Panel
Fig. D3
CN104
CLN104
CLN105
CN111
CN113
CN112

7-1
BLOCK DIAGRAMS
System Control Block Diagram
L3202BLS
FUNCTION CBA
IC333 (TV MICRO CONTROLLER)
3
21
KEY-IN-122
CN104 CLN104
KEY SWITCH
11
KEY-IN-1
REMOTE
RESET RESET
Q151
P-ON+3.3V(D)
42 43 X161
27MHz
XIN
XOUT
MAIN CBALCD MAIN CBA UNIT
4
KEY-IN-211
KEY-IN-2
22 18 17
BACKLIGHT-SW
19 5
BACKLIGHT-ADJ
21 3
P-ON-H16 8 VOLUME15 9 AUDIO-MUTE
13 11
INPUT-012 12 INPUT-111 13 S-SW717 SCL618 SDA519
BACKLIGHT-SW
BACKLIGHT-ADJ
P-ON-H
VOLUME
AUDIO-MUTE
SDA SCL
INPUT-0 INPUT-1
S-SW
SCL SDA
20 35 31 40 19 32 41 TO POWER SUPPLY
BLOCK DIAGRAM TO IF/VIDEO BLOCK DIAGRAM TO AUDIO BLOCK DIAGRAM
BACKLIGHT-SW
BACKLIGHT-ADJ
P-ON-H
VOLUME
AUDIO-MUTE
INPUT-0 INPUT-1
S-SW
SCL
SDA
TO LCD BACKLIGHT BLOCK DIAGRAM
CN102B CN102A
SDA 2 SCL 1
CN112(NO CONNECTION)
IC171 (MEMORY)
SCL 6
SDA 5
7
WP
Q131
3.3V<-->5V CONVERTER
BUS-OPEN 4
NO PART MOUNTED FOR CN112
23
BUS-OPEN
P-ON-H2(NU)
14 1016
P-ON-H2
12
P-25V-ON P-25V-ON
TO POWER SUPPLY BLOCK DIAGRAM
KEY SWITCH
IR SENSOR CBA
CLN105 REMOTE
SENSOR
RCV102
AL +5V
D102
POWER
Q102
P-ON-H44
CN105 REMOTE33
INVERTER CBA
BACKLIGHT-ADJ
99
CN411 CLN411
BACKLIGHT-SW
88
P-ON-H11 11 P-ON-H
AFT-IN10 145AFT-IN
80
TUNERCLK
Q301
BUFFER AFT-IN
BUS-OPEN519
CN103B CN103A
CN113 (NO CONNECTION)
SDA
2SCL 1
BUS-OPEN
4CN113 IS USED
FOR ADJUSTMENT AT FACTORY
P-ON-H
FSC123
FSC

7-2 L3202BLIF
IF/Video Block Diagram
TO AUDIO BLOCK DIAGRAM
CN103A TO
LCD BLOCK DIAGRAM CN103B
CVBS11 S-VIDEO-C7 S-VIDEO-Y9
INPUT-0(INV) INPUT-1(INV)
SAW FILTER
TU1 SF11
IF
AGC
SDA
SCL
1
7
3 2
SIF
MAIN CBA
VIDEO SIGNAL AUDIO SIGNAL
TO AUDIO BLOCK DIAGRAM
JK706 VIDEO-Y IN JK707 VIDEO-Pb/Cb IN JK708 VIDEO-Pr/Cr IN
JK703 VIDEO1 -IN JK701 S-VIDEO IN
BUFFER
Q32
SDA
TO SYSTEM CONTROL BLOCK DIAGRAM
SCL
S-SW
CY
CN103A TO
LCD BLOCK DIAGRAM CN103B
VIDEO-Y5 VIDEO-Pb/Cb
3
VIDEO-Pr/Cr
1
3
IC781 (INPUT SELECT)
5
Q703
4
13 12
Q702
14
1 2
Q701
15
SW CONTROL
10
911
INPUT-0 INPUT-1
TO SYSTEM CONTROL BLOCK DIAGRAM
Q707 Q708
Q704 Q705
Q706
(TUNER UNIT)
BUFFER
BUFFER
BUFFER
BUFFER
BUFFER
BUFFER
WF7
WF8
WF9
WF10 WF11 WF12
CF31
IC31 (IF SIGNAL PROCESS)
VIF AMP VIDEO
DET
VCO
4.5MHz FILTER
RF AGC
AMP
SIF AMP
16
13 18
17 478
1
XTAL-IN 14
TO SYSTEM CONTROL BLOCK DIAGRAM
AFT-IN
5
SIF TRAP
11
IF AGC DET
AFT EQ
AMP
2
DEFEAT
FSC

7-3
Audio Block Diagram
L3202BLA
MAIN CBA
AUDIO SIGNAL
AUDIO-MUTE
VOLUME TO SYSTEM
CONTROL BLOCK
INPUT-0(INV) INPUT-1(INV)
SCL SDA
IC852 (INPUT SELECT)
SW CTL
3
11 15 12
4 1
9 10
STEREO FILTER 75uS
DE-EMPH
dBX DE-EMPH
L+R FILTER
WIDE BAND FILTER WIDE BAND
RMS DET WIDE BAND
EXPAND
SPECTRAL EXPAND SPECTRAL RMS DET
SPECTRAL FILTER
OFFSET CANCEL
L-CH R-CH
MATRIX AGC
OFFSET CANCEL L-R
FILTER (L-R)/SAP
SW
SAP FILTER
I2C DECORDER
SAP DEMOD SAP OUT
FILTER
29 30
TO IF/VIDEO BLOCK DIAGRAM
TUNER
TUNER
(L-CH) (R-CH)
21 27 24
IC851 (MTS/SAP AUDIO SIGNAL PROCESS)
AUDIO1(L) -IN JK704
SIF
JK705 AUDIO1(R) -IN JK709 AUDIO2(L) -IN JK710 AUDIO2(R) -IN
OFFSET CANCEL
14
IC801(AUDIO AMP)
7
VOLUME
11
AMP AMP
MUTE /STANDBY CONTROL
6 1
(R-CH) (L-CH)
2
Q802
Q803
5
RF
JK801 HEADPHONE JACK
SP801 SPEAKER R-CH
CN801
SP-R 1
GND 2
SP802 SPEAKER L-CH
CN802 CLN802
CLN801
SP-L 1
GND 2
+5V
TO IF/VIDEO BLOCK DIAGRAM
13
2
WF6
AUDIO1
AUDIO2
AUDIO1 AUDIO2
SIF/BB SW
INPUT VCA
SIF DEMOD
14
5
P-ON-H

7-4
LCD Block Diagram
L3202BLLCD
CN311
TO IF/VIDEO BLOCK DIAGRAM CN103A
OR(0)34 OR(1)33
LCD MAIN CBA UNIT
VIDEO SIGNAL
CVBS 13
S-VIDEO-C 17
CN103B
IC333 (LCD DRIVE / SIGNAL PROCESS)
68 49 71
S-VIDEO-Y 15
TO IF/VIDEO BLOCK DIAGRAM CN103A
VIDEO-Y 19
VIDEO-Pb/Cb
21
CN103B
LCD MODULE
OR(2)32 OR(3)31 OR(4)30 OR(5)29 OG(0)27 OG(1)26 OG(2)25 OG(3)24 OG(4)23 OG(5)22 OB(0)20 OB(1)19 OB(2)18 OB(3)17 OB(4)16 OB(5)15 ER(0)6 ER(1)5 ER(2)4 ER(3)3 ER(4)2 ER(5)1 EG(0)50 EG(1)49 EG(2)48 EG(3)47 EG(4)46 EG(5)45 EB(0)43 EB(1)42 EB(2)41 EB(3)40 EB(4)39 EB(5)38 OFFEV12 STV113 CLKV14 HMS1-E7 HMS1-013 STH142 POL43 LP44
CN311
170
60 52 74
169
166
165
164
163
162
161
157
156
155
154
153
152
148
147
146
145
138
137
136
135
130
129 128
127
126
125
118
117
116
115
114
113
108
107
101
105
106
144
139
172
173
174
A/D
VIDEO SIGNAL PROCESS
LCD RGB SIGNAL PROCESS
R B G Y Pb/Cb Pr/Cr B(EVEN)
G(EVEN) R(EVEN)
B(ODD) G(ODD) R(ODD)
CN312
A/D A/D A/D A/D A/D
VIDEO-Pr/Cr
23
R B G
WF3
ODDINV
EVENINV
STH-1
POL
LP
OFFEV
STV1
CLKV
CLKH10
143
CLKH1
WF1
WF5
WF2
CVBS C Y
R201
R202
R394
R365
R392
WF4

7-5
Power Supply Block Diagram
L3202BLP
4A/125V
F601 4A/125V LINE
FILTER
L601
AC601 AC CORD
BRIDGE RECTIFIER
D605 - D608
HOT COLD
T601
15 12 13 14 11 16
7
4 3
1 2
IC601 ERROR VOLTAGE DET
Q601
Q603
SWITCHING
CONTROL
SWITCHING
MAIN CBA
5 3 2
PANEL+3.3V
46
PANEL+10.8V
55
PANEL+25V73 PANEL-6V82
VT+33V
Q511
Q513
IC533
+5V REG.
HOT CIRCUIT. BE CAREFUL.
LINE FILTER
L602
AL+13V
Q509
Q505
Q510
Q512
CN101A
P-25V-ON21 3 AL+5V22 2
CN102A
Q502
Q501
IC671
+5V REG.
IC672
+5V REG.
REG+5V
REG+5V
IC531
+7V REG.
Q531
P-ON-H AL+7V(D)
AL+5V
9
10
AL+21V
TO SYSTEM CONTROL BLOCK DIAGRAM
TP401
+21V
Q633
CN101B
PANEL+3.3V PANEL+10.8V PANEL+25V PANEL-6V
LCD MAIN CBA UNIT
P-25V-ON AL+5V
CN102B
TO SYSTEM CONTROL BLOCK DIAGRAM TO LCD BACKLIGHT BLOCK DIAGRAM
CAUTION ! Fixed voltage (or Auto voltage selectable) power supply circuit is used in this unit. If Main Fuse (F601) is blown , check to see that all components in the power supply circuit are not defective before you connect the AC plug to the AC power supply. Otherwise it may cause some components in the power supply circuit to fail.
For continued protection against risk of fire, replace only with same type 4 A, 125V fuse.
CAUTION ! : ATTENTION :Utiliser un fusible de rechange de même type de 4A, 125V.
4A/125V
NOTE: The voltage for parts in hot circuit is measured using hot GND as a common terminal.

7-6
LCD Backlight Block Diagram
L3202BLIV
CURRENT CONTROL SWITCH
CURRENT CONTROL SWITCH
BACKLIGHT-SW
RL401
Q421, Q426
IC401 (DC-AC INVERTER CONTROL)
Q403
Q412
VCC
1 2
T450
CN450
LCD MODULEINVERTER CBA
P-ON-H BACKLIGHT-ADJ
Q433
Q411
BACK LIGHT BACK LIGHT BACK LIGHT
26 27 23 24 28 14 11
9
13 12
1
16
+8V REG.
OUTPUT LOGIC1 OUTPUT LOGIC2
LOGIC
OVER VOLTAGE PROTECT
SLOW START
OSC
PWM2 PWM1
STANDBY MODE SW
4 5 7
OVER VOLTAGE PROTECTOR
Q451,452
OVER VOLTAGE PROTECTOR
Q454,455
7 6 98 1 2
13 14
T490 CN490
OVER VOLTAGE PROTECTOR
Q491,492
1 2
1 2
T460 CN460
OVER VOLTAGE PROTECTOR
Q461,462
10
IC402
(OP AMP)
TO SYSTEM CONTROL BLOCK DIAGRAM
AL+21V
9 7
3 1
6 4 2 5
10
8
9 7
3 1
6 4 2 5
10
8
9 7
3 1
6 4 2 5
10
8
TO POWER SUPPLY BLOCK DIAGRAM
MAIN CBA
AL+21V22
CN411 CLN411
AL+21V11 AL+21V33

8-3
Main 1/4 Schematic Diagram
L3202SCM1
MAIN 1/4
Ref No. Position
IC531 D-4
IC533 E-3
IC671 E-2
IC672 E-2
Q501 C-4
Q502 C-4
Q503 B-3
Q505 C-3
Q509 C-3
Q510 B-2
Q511 C-3
Q512 C-2
Q513 C-2
Q531 D-3
Q633 E-1
CN411 F-4
CN101A A-4
CN102A A-3
TP401 E-4
ICS
TRANSISTORS
TEST POINT
CONNECTORS