ViewSonic va720-1 User manual
Service Manual
ViewSonic VA720-1
Model No. VLCDS23895-3W
17” Color TFT LCD Display
ViewSonic381 Brea Canyon Road, Walnut, California 91789 USA - (800) 888-8583
VE175/b-1
(VA720-1_SM_542 - Rev. 1a – May 2002)
ViewSonic
®
Copyright
Copyright
¤
2002 by ViewSonic Corporation. All rights reserved. No part of this publication may be
reproduced, transmitted, transcribed, stored in a retrieval system, or translated into any language or
computer language, in any form or by any means, electronic, mechanical, magnetic, optical, chemical,
manual or otherwise, without the prior written permission of ViewSonic Corporation.
Disclaimer
ViewSonic makes no representations or warranties, either expressed or implied, with respect to the
contents hereof and specifically disclaims any warranty of merchantability or fitness for any particular
purpose. Further, ViewSonic reserves the right to revise this publication and to make changes from time to
time in the contents hereof without obligation of ViewSonic to notify any person of such revision or changes.
Trademarks
ViewSonic is a registered trademark of ViewSonic Corporation.
All other trademarks used within this document are the property of their respective owners.
Revision History
Revision Date Description Of Changes Approval
1.a 5/28/02 Initial Issue – DCN2251 K. Yang
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VE175/b
TABLE OF CONTENTS
1. PRECAUTIONS & SAFETY NOTICES....................................................................................1
2. SERVICE TOOLS & EQUIPMENT REQUIRED .....................................................................2
3. SPECIFICATIONS .................................................................................................................3~4
4. EXPLODED VIEW & PARTS LIST......................................................................................5~6
5. BLOCK DIAGRAM ...................................................................................................................7
6. SCHEMATIC DIAGRAMS..................................................................................................8~15
7. THEORY OF OPERATION.....................................................................................................16
8. WIRING DIAGRAM................................................................................................................17
9. PCB LAYOUT ....................................................................................................................18~23
10. TROUBLE SHOOTING FLOW CHART ........................................................................24~27
11. ADJUSTMENT……………………. .................................................................................28~30
12. ELECTRICAL PARTS LIST............................................................................................31~38
ViewSonic Corporation iiiConfidential – Do Not Copy
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1. PRECAUTIONS & SAFETY NOTICES
1. PRECAUTION AND NOTICES
1.1. SAFETY PRECAUTIONS
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1.2. PRODUCT SAFETY NOTICE
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1.3. SERVICE NOTES
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2. SERVICE TOOLS & EQUIPMENT REQUIRED
2. SERVICE TOOL & EQUIPMENT REQUIRED
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3. SPECIFICATIONS
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3. SPECIFICATIONS
3.1. PRODUCT SPECIFICATIONS
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3.2. FACTORY SUPPORTING MODES
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3.3. D-SUB CONNECTOR
9( @<2-"(9:4
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12345
678910
11 12 13 14 15
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4.1. EXPLODED VIEW
X4
5B06
5B05
5B01
1F29
X21F30
5B03
X35B07
2C20
5B02 X4
5B09
5B08
2C05
2C04
2C22
2C03
2C01
1F31 X2 X5
2C21
1F12 P953 X21F13
1F14 I/O CABLE
1F20
1F18
1F06 X4
1F07X2
1F16 X2
1F18
1F27
1F26
V901
1F05
1F17X6
1F09 X4
1F02
1F01
1F19
1F03
1F04 X2
2C03
1F22
1F28
1F23 X2
1F15X2 X4
1F08
1F21
1F10 1F11
FIG.1
FIG.2
FIG.2
FIG.1
MAIN PCB ASS'Y
1F24
1F25
FIG.3
FIG.3
U901
9H01
9S01
I801
D804
9S02
POWER PCB ASS'Y
FIG.4
9H02
CON. PCB ASS'Y
PCB
9R01
D701
FIG.4
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4. EXPLODED VIEW & PARTS LIST
4.2. EXPLODED VIEW PARTS LIST
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! "
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$($ $$)
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AC-DC
POWER
AC INPUT 12V DC-DC
CONVERTER
I101,D101,L102
5V
REGULATOR
I102
3.3V
INVERTER
U901
VGA INPUT
P103,P105
DDC
I105
ADC
I103
CONTROLLER IC
I109
Micro
CONTROLLER
I112
KEY PAD
&
LED
PANEL
DISPLAY
HIGHT
VOLTAGE
OSC
X101
EERROM
I119
LVDS
INTERFACE
I117,I118
12V
5. BLOCK DIAGRAM
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RA SI8050:---R108 NC
RB LM2596:---R108 10 R
I102
RA:AMC7585-3.3ST
RB:AIC1084-33CM
6. SCHEMATIC DIAGRAM
6.1. POWER REGULATER
Q20-G
Q20-SQ20-D
PSC1 5
PSC0 5
5V
12V
5V
LCD_VCC
12V
3V3_B
3V3_A
12V
L101
FERRITE
C105
470uF/25v
D111
5.6V
1 2
R106
2k
L136
NC Q101
HUF76107D
1
32
R107
2k
C102
0.1u
L102 30UH
C109
0.1u
R102
20K
C101
0.1u
Q104
MMBT3904L
12
3
I101 LM2596
1
2
3
4
5
VIN
SW
GND
FB
SHDN
C113
330uF/25v
C106
0.1u
C103
470uF/25v
P101
CON4
1
2
3
4
C114 0.1u
R105
20K
C104
470uF/25v
I102
AIC1084
3
1
2
INPUT
GND
OUTPUT
C108
330uF/25v
D101
B340
P102
NC
C110
330uF/25v
L103 FERRITE
C107
220p
C111
0.1u
R108
10
Q103
HUF76107D
1
32
R103 2K
R104
2K
Q102
MMBT3904L
12
3
L104 NC
C112
0.1u
C115
0.1u
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B
G
R
6.2. AD9883-140
R_IN03
R_IN01
R_IN02
R_IN00
G_IN00
G_IN01
G_IN03
G_IN02
B_IN03
B_IN00
B_IN01
B_IN02
B_IN05
B_IN06
B_IN04
B_IN07
G_IN07
G_IN05
G_IN06
G_IN04
R_IN05
R_IN04
R_IN07
R_IN06
HSYNC_IN
DDC_SCL
DDC_SDA
5V_DDC
HSYNC_IN
VSYNC_IN
VSYNC_IN
VGA_SDA
VGA_SCL
VGA_HS
VGA_VS
5V_DDC
VGA_HS
VGA_SCL
VGA_SDA
VGA_VS
R_IN0[0..7] 4
G_IN0[0..7] 4
B_IN0[0..7] 4
VCLK00 4,5
MCU_SCL15
DDC_SDA5
DDC_SCL5
MCU_SDA15
VSYNC_A 6
HSYNC_A 6
ASIC_H 4
ASIC_V 4,5
VDD_33
P3_3V
5V
VDD_33
VD_33
P3_3V
3V3_A
3V3_A
VD_33
3V3_A
3V3_A
3V3_A
5V
5V
D102
5.6V
1 2
C152
0.1u
L10832R
L10732R
C153
0.1u
C129
NC
C123
0.1u
C138
NC
C155
0.1u
C154
22uF/25v
C156
0.1u
C157
0.1u
C158
0.1u
C159
0.1u
C160
0.1u
C161
0.1u
C165
0.1u
C162
0.1u
C163
0.1u
C164
0.1u
C132
NC
I103
AD9883
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
GND
G7
G6
G5
G4
G3
G2
G1
G0
GND
VDD
B7
B6
B5
B4
B3
B2
B1
B0
GND
GND
VDD
VDD
GND
GND
VD
VD
GND
COAST
HSYNC
VSYNC
GND
FILT
PVD
PVD
GND
MIDSCV
CLAMP
VD
GND
GND
VD
BAIN
GND
VD
VD
GND
GAIN
SOGIN
GND
VD
VD
GND
RAIN
A0
SCL
SDA
REF BYPASS
VD
GND
GND
VD
GND
VSOUT
SOGOUT
HSOUT
DATACLK
GND
VDD
R7
R6
R5
R4
R3
R2
R1
R0
VDD
VDD
GND
L111200R
C143
100uF/16v
C131 47n
C124 47n
C127 47n
R124
2k
R121
10k
C137
100p
C136
47p
C144
0.1u
I104
74LVC14
1
2
3
4
5
6
7 8
9
10
11
12
13
14
A1
B1
A2
B2
A3
B3
GND B4
A4
B5
A5
B6
A6
VCC
R120
10k
R123
2k
C139
NC
R110 22
C128
NC
C145
0.1u
RP1 33
1
2
3
45
6
7
8
C133
22p
C130
22p
C126
22p
R111 2.7k
C121
8.2n
RP6 33 1
2
3
45
6
7
8
RP4 33 1
2
3
45
6
7
8
C122
82n
RP5 33
1
2
3
45
6
7
8
R114 33
C120
33p
C134
0.1u
RP3 33
1
2
3
45
6
7
8
R116 33
C149
0.1u
L1090 R
RP2 33 1
2
3
45
6
7
8
C142
33p
C151
0.1u
C147
0.1u
C146
22uF/25v
C148
0.1u
R128 100
R127
820
R129 100
C150
0.1u
L110200R
D106
5.6V
1 2
R126
820
D107
5.6V
1 2
P104
NC
1
2
3
4
1
2
3
4
R122 33
R130 10
C140 0.1u
I105
24LC21
1
2
3
45
6
7
8NC
NC
NC
GNDSDA
SCL
VSYNC
VCC
R113
75
C141
33p
C135
0.1u
L10632R
R115
75
R117
75
R112 33 C125
NC
D103
5.6V
1 2
P105
CON6
1
2
3
4
5
6
P103
CON7
1
2
3
4
5
6
7
R186 NC
R181 0
R125 33
D104
1N4148 D105
1N4148
R119 33
R118 33
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6.3. SCALER-SD1210
R_IN00
R_IN01
R_IN02
R_IN03
R_IN04
R_IN05
R_IN06
R_IN07
R_IN17
G_IN00
G_IN01
G_IN02
G_IN03
G_IN04
G_IN05
G_IN06
G_IN07
B_IN00
B_IN01
B_IN02
B_IN03
B_IN04
B_IN05
B_IN06
B_IN07
BB7
BB6
BB5
BB4
BB3
BB2
BB1
BB0
GA4
GA1
RA2
GA5
RB4
RB1
RA6
GB3
GA0
GA3
RA1
GB7
RB3
RA5
GB2
RB7
GA2
RA0
RB2
RA4
GB1
GA7
RB6
RB0
GB5
GB6
RA3
GB0
GA6
RB5
RA7
GB4
BA5
BA6
BA0
BA4
BA3
BA7
BA2
BA1
BA[0..7] 7,8
BB[0..7] 7,8
R_IN0[0..7]2
G_IN0[0..7]2
B_IN0[0..7]2
OSD_HS 5
OSD_VS 5
LCD_DE 7,8
LCD_CLK 7,8
LCD_VS 7,8
LCD_HS 7,8
FCLK1 6
VCLK1 6
FBLK 5
OSD_B 5
OSD_G 5
OSD_R 5
12MHz 5
ROM_SCL5ROM_SDA5ASIC_SCL5ASIC_SDA5ASIC_RST5
ASIC_H2ASIC_V2,5
EERW5
GA[0..7] 7,8
GB[0..7] 7,8
HSYNC_X 6
RB[0..7] 7,8
RA[0..7] 7,8
DE_SENSE 5
VCLK00 2,5
3_3VS
3_3VS
5V
3V3_B
R146 33
R197 33
R150 33
R142 33
C201
22P
C203
NC
C206
330uF/25v
C207
0.1u
C208
0.1u
C209
0.1u
C210
0.1u
C211
0.1u
C212
0.1u
C213
0.1u
C214
0.1u
C215
0.1u
C216
0.1u
R154 100
C217
0.1u
C218
0.1u
C219
0.1u
C220
0.1u
I111
NC
1
2
3
4 5
6
7
8
A0
A1
A2
VSS SDA
SCL
WP
VDD
R149 33
R147 33
RP24 33
1
2
3
4 5
6
7
8
I110
24C08
1
2
3
4 5
6
7
8
A0
A1
A2
VSS SDA
SCL
WP
VDD
RP23 33
1
2
3
4 5
6
7
8
R158 33
R157 33
R156
4.7k
C202
22P
R155
4.7k
C205
0.1u
RP22 33
1
2
3
4 5
6
7
8
R141 33
I109
SD1210-2
1
2
3
4
5
6
7
8
9
10
11
12
14
13
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
B_IN10
B_IN11
B_IN12
B_IN13
DATA_SEL
B_IN14
B_IN15
B_IN16
B_IN17
ROM_SCL
ROM_SDA
GND
CPU_SDA
CPU_SCL
PWM_CTL
CLK_1M
VDD
CLK_1M_O
RESET_B
R_OSD
G_OSD
B_OSD
EN_OSD
SCAN_EN
TEST_EN
VCLK01
FCLK0
VCLK00
FCLK1
VCLK1
HSYNC_O
VSYNC_O
DCLK_OUT
DE_OUT
GND
VDD
R_OUT0_E
R_OUT1_E
R_OUT2_E
R_OUT3_E
HSYNC_X
VSYNC_X
GND
R_OUT4_E
VDD
VDD
R_OUT5_E
GND
R_OUT6_E
R_OUT7_E
GND
R_OUT0_O
R_OUT1_O
R_OUT2_O
R_OUT3_O
VDD
R_OUT4_O
R_OUT5_O
R_OUT6_O
R_OUT7_O
GND
G_OUT0_E
G_OUT1_E
G_OUT2_E
G_OUT3_E
G_OUT4_E
VDD
G_OUT5_E
G_OUT6_E
G_OUT7_E
GND
GND
G_OUT0_O
G_OUT1_O
G_OUT2_O
G_OUT3_O
VDD
G_OUT4_O
G_OUT5_O
G_OUT6_O
G_OUT7_O
GND
GND
B_OUT0_E
B_OUT1_E
B_OUT2_E
B_OUT3_E
B_OUT4_E
B_OUT5_E
B_OUT6_E
VDD
VDD
B_OUT7_E
GND
B_OUT0_O
B_OUT1_O
B_OUT2_O
B_OUT3_O
VDD
B_OUT4_O
B_OUT5_O
B_OUT6_O
B_OUT7_O
GND
R_IN00
R_IN01
R_IN02
R_IN03
VDD
R_IN04
R_IN05
R_IN06
R_IN07
R_IN10
R_IN11
GND
R_IN12
R_IN13
VDD
R_IN14
R_IN15
R_IN16
R_IN17
GND
G_IN00
G_IN01
G_IN02
G_IN03
VDD
G_IN04
G_IN05
ADC_CLK0
G_IN06
G_IN07
GND
G_IN10
G_IN11
ADC_CLK1
G_IN12
G_IN13
VDD
G_IN14
G_IN15
G_IN16
G_IN17
GND
B_IN00
B_IN01
B_IN02
VDD
B_IN03
B_IN04
B_IN05
B_IN06
B_IN07
GND
HSYNC_I
VSYNC_I
DE_IN
VDD
L118 200R
RP30 33
1
2
3
45
6
7
8
RP29 33
1
2
3
4 5
6
7
8
RP28 33
1
2
3
4 5
6
7
8
RP27 33
1
2
3
4 5
6
7
8
RP26 33
1
2
3
4 5
6
7
8
RP25 33
1
2
3
4 5
6
7
8
R145 33
R143 33
R153 33
RP21 33
1
2
3
4 5
6
7
8
RP20 33
1
2
3
4 5
6
7
8
RP19 33
1
2
3
4 5
6
7
8
L117 70R
R148 33
R152 33R151 33
R144 33
C204
22P
ViewSonic Corporation 10 Confidential – Do Not Copy
VA720-1
VE175/b
SO-8
TCM810
MTV230
PLCC-44 SOCKET
P114 FOR I112
6.4. MCU-SM0230
LED_ORG
LED_GRN
UP
MCU_SCL1
MCU_SDA1
ASIC_SCL
ASIC_SDA
ON-OFF
AMBER
AMBER
SD_MODE
SD_MODEX2
X2
DOWN
PSC1
UP
DOWN
MENU
ON-OFF
ENTER
CW6
CW3
LED_GRN
CW7
LED_ORG
CW6
CW2
CW1
CW4
CW5
CW7
CW3
CW2
CW1
CW4
GRN GRN
CW5
MENU
ENTER
FBLK4OSD_B4OSD_G4OSD_R4OSD_CLK6OSD_HS4OSD_VS4
PSC01
ASIC_RST4
MCU_VSIN6
MCU_HSIN6
DDC_SCL2
DDC_SDA2
BL_BRI
8
BL_ONOFF 8
MCU_SCL1 2
MCU_SDA1 2
ROM_SCL 4
ROM_SDA 4
ASIC_SCL 4
ASIC_SDA 4
ASIC_V2,4
INPUTSEL6
DE_SENSE 4
12MHz4
VCLK00 2,4
PSC1
1
EERW
4
PDO 3
PD 3
5V
3V3_A
3V3_A
3V3_A
3V3_A
3V3_A
5V
3V3_A
5V
5V
3V3_A
R172 220
R173 220
Q108
MMBT3904L
12
3
R159
1k
R187 0
R195 NC
P106
NC
1
2
3
4
5
6
7
8
P112CON 8
1
2
3
4
5
6
7
8
L121200R
C231
220P
C232
220P
L119200R
L120200R
L122200R
L123200R
C234
NC
R166
510
I112
SM0230
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
ROUT
XIN
OSDHS
OSDVS
P4.7/VBLANK
P4.6/HBLANK
X1
X2
P4.5
P4.4
P4.3
P4.2
P4.1/VSYNC
P4.0/HSYNC
P3.0/Rxd/HSCL
P3.1/Txd/HSDA
P3.2/INT0
VDD
RST
VSS
P3.4/T0
P3.5/T1
P6.0/ISCL
P6.1/ISDA
P1.0
P1.1
P1.2
P1.3
P1.4
P1.5
P1.6
P1.7
P5.0/AD0
P5.1/AD1
P5.2/AD2
P5.3/AD3
P5.4/DA0
P5.5/DA1
P5.6/DA2
P5.7/DA3
INT/P6.2
FBKG
BOUT
GOUT
R163
1k
C222
22p
RP33
4.7k
18
7
6
5
2
3
4
C226
1u
R161 33
X1
12MHz
12
C223
220p
R175 100
I114
NC
1
2
3
4 5
6
7
8
A0
A1
A2
VSS SDA
SCL
WP
VDD
RP31
4.7k
18
7
6
5
2
3
4
C236
1u
R179 33
R164 10k
C235
0.1u
R17175
RP32
4.7k
18
7
6
5
2
3
4
U1
NC
1
2
3
GND
RESET
VCC
C233
NC
Q106
MMBT3904L
12
3
RP34
4.7k
18
7
6
5
2
3
4
R165 10k
Q105
MMBT3904L
12
3
RP35
4.7k
18
7
6
5
2
3
4
C225
0.1u
C227 22p
R162 100
C221
NC
R167 4.7k
C224
0.1u
C229
22p
R170 75
R160 33
C237 0.1u
R177
10k
D110
1N4148
R169 1M
C230 0.1u
R168 0
C228 NC
I119
24C16 DIP
1
2
3
45
6
7
8A0
A1
A2
VSSSDA
SCL
WP
VDD
RP36
4.7k
18
7
6
5
2
3
4
C364NC
C367NC
C368NC
C369NC
C365NC
C370NC
C366
NC
I113
SN74LVC125A
1
2
3
4
5
6
7 8
9
10
11
12
13
14
1OE_
1A
1Y
2OE_
2A
2Y
GND 3Y
3A
3OE_
4Y
4A
4OE_
VCC
R176 100
P107
NC
1
2
3
4
5
6
1
2
3
4
5
6
R178 33
ViewSonic Corporation 11 Confidential – Do Not Copy
VA720-1
VE175/b
XGA
L134 SXGA
R199-0
6.5. PLL
VSYNC_A2
INPUTSEL5
OSD_CLK 5
FCLK14
VCLK1 4
HSYNC_A2MCU_HSIN 5
HSYNC_X4
MCU_VSIN 5
5V
3v3_B
3V3_A
R199
0
C238
0.1u
C242
NC
L126 32R
C241
NC
L134
NC
I116
AV9173-01
1
2
3
4 5
6
7
8
FBIN
IN
GND
FSO OE
CLK1
VDD
CLK2
C244
10uF/25v
L127 200R
C245
0.1u
C243
22p
R185
100
R180
0
R182
NC
R183
NC
R184
0
R188
0
I115 NC
74HC4053
11
10
9
12
13
2
1
5
3
14
15
4
6
7
16
8
S1
S2
S3
1Y0
1Y1
2Y0
2Y1
3Y0
3Y1
1Z
2Z
3Z
E_
VEE
VCC
GND
ViewSonic Corporation 12 Confidential – Do Not Copy
VA720-1
VE175/b
DF14-30P
2nd_pixel
1st_pixel
2nd_pixel
1st_pixel
6.6. LVDS
LCD_HS
LCD_VS LCD_DE
3V3LVDSA
3V3LVDSP
LCD_VS
LCD_CLK
LCD_CLK
LCD_HS
3V3LVDSP
LCD_DE
3V3LVDSA
TXO0M
TXO0P
TXO1M
TXO1P
TXO2M
TXO2P
TXOCKM
TXOCKP
TXO3M
TXO3P
TXE0M
TXE0P
TXE1M
TXE1P
TXE2M
TXE2P
TXECKM
TXECKP
TXE3M
TXE3P
TXE0M
TXE0P
TXE1M
TXE1P
TXE2M
TXE2P
TXO2M
TXO2P
TXOCKM
TXO3P
TXO3M
TXOCKP
TXO0P
TXE3M
TXECKM
TXE3P
TXECKP
TXO0M
TXO1P
TXO1M
RB4 4,8
RB3 4,8
RB2 4,8
RB1 4,8
RB0 4,8
RB6 4,8
LCD_CLK 4,8
LCD_DE 4,8
RB74,8 RB54,8 GB04,8
GB14,8 GB24,8 GB64,8
GB74,8 GB34,8 GB44,8
GB54,8 BB04,8 BB64,8
BB74,8 BB14,8 BB24,8
BB34,8
BB54,8
LCD_HS4,8 LCD_VS4,8
BB44,8
RA4 4,8
RA2 4,8
RA1 4,8
RA0 4,8
RA6 4,8
RA74,8 RA54,8 GA04,8
GA14,8 GA24,8 GA64,8
BA74,8 BA14,8 BA24,8
BA34,8 BA44,8 BA54,8
RA3 4,8
GA34,8 GA44,8
BA64,8
GA74,8
GA54,8 BA04,8
3V3LVDSP
3V3LVDSP
3V3LVDSD
3V3LVDSD
3V3LVDSA
3V3LVDSD
3V3LVDSA
3V3_B
LCD_VCC
C261
0.1u
L128
200R
L129
200R
L130
200R
L135
200R
C259
0.1u
C262
0.1u
C255
0.1u
C256
0.1u
C252
0.1u
C253
0.1u
C254
0.1u
R191
NC
R192
0
P108
CON30
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
I117
SN75LVDS83
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28 29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
VCC
D5
D6
D7
GND
D8
D9
D10
VCC
D11
D12
D13
GND
D14
D15
D16
CLKSEL
D17
D18
D19
GND
D20
D21
D22
D23
VCC
D24
D25 GND
D26
CLKIN
SHTDN
PLLGND
PLLVCC
PLLGND
LVDSGND
Y3P
Y3M
CLKOUTP
CLKOUTM
Y2P
Y2M
LVDSGND
LVDSVCC
Y1P
Y1M
Y0P
Y0M
LVDSGND
D27
D0
D1
GND
D2
D3
D4
R189
NC
R190
0
I118
SN75LVDS83
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28 29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
VCC
D5
D6
D7
GND
D8
D9
D10
VCC
D11
D12
D13
GND
D14
D15
D16
CLKSEL
D17
D18
D19
GND
D20
D21
D22
D23
VCC
D24
D25 GND
D26
CLKIN
SHTDN
PLLGND
PLLVCC
PLLGND
LVDSGND
Y3P
Y3M
CLKOUTP
CLKOUTM
Y2P
Y2M
LVDSGND
LVDSVCC
Y1P
Y1M
Y0P
Y0M
LVDSGND
D27
D0
D1
GND
D2
D3
D4
C246
0.1u
C248
22uF/25v
C257
22uF/25v
C260
22uF/25v
C247
47uF/25vC249
0.1u
C250
0.1u
C258
0.1u
C251
0.1u
ViewSonic Corporation 13 Confidential – Do Not Copy
VA720-1
VE175/b
GREEN ORANGE
KEY PAD
6.7. PANEL CONNECTOR
LCD_VS
LCD_HS
LCD_DE
LCD_CLK
GB5
GB3
RB1
RB7
RB2
RB5
RB4
RB3
GA3
GA7
GA4
GA6
GA5
GA2
GA1
GA0
RB0
RB6
GB0
GB1
GB2
GB4
GB6
GB7
BA5
BA2
BA7
BA0
BA1
BA6
BA4
BA3
RA5
RA0
RA2
RA6
RA1
RA7
RA3
RA4
BB3
BB1
BB5
BB6
BB2
BB4
BB0
BB7
RA0
RA1
RA2
RA3
RA4
RA5
RA6
RA7
GA0
GA1
GA3
GA2
GA4
GA5
GA7
GA6
BA0
BA2
BA1
BA5
BA7
BA4
BA3
BA6
LCD_VS
LCD_CLK
LCD_DE
LCD_HS
RB0
RB7
RB5
RB6
RB2
RB3
RB1
RB4
BB1
BB0
GB1
GB5
BB2
BB4
BB3
GB6
GB4
GB2
GB0
GB7
GB3
BB6
BB5
BB7
LCD_VCC
LCD_VCC
IW1
IW2
IW3
IW3
IW2
IW1
DOWN
2
PSM/LED
PWR/LED
UP
1
PWR/SW
BA[0..7]4,7
GA[0..7]4,7
RA[0..7]4,7
BB[0..7]4,7
GB[0..7]4,7
RB[0..7]4,7
LCD_CLK 4,7
LCD_DE 4,7
LCD_VS 4,7
LCD_HS 4,7
BL_ONOFF 5
BL_BRI 5
LCD_VCC
3V3_A
12V
C272 22P
P113
NC
1
2
3
4
5
6
1
2
3
4
5
6
C359NC
C358NC
C360NC
C273 22P
C276 22P
S701
S703S704S705
C270 22P
C271 22P
D701S702
P701
8 HEADER
1
2
3
4
5
6
7
8
C279
0.1u
R193
1k
Q107
MMBT3904L
12
3
C288
0.1u
C278
330uF/25v
P109
CON6
1
2
3
4
5
6
1
2
3
4
5
6
R194 1K
L132 200R
L133 200RC274 22P
C275 22P
C277 22P
C280 22P
C281 22P
C282 22P
C283 22P
C284 22P
C285 22P
C286 22P
C287 22P
L131 FERRITE
C289 22P
C290 22P
C291 22P
C292 22P
C293 22P
C294 22P
C295 22P
C296 22P
C297 22P
C300 22P
C301 22P
C298 22P
C299 22P
C302 22P
C303 22P
C304 22P
C305 22P
C306 22P
C307 22P
C308 22P
C309 22P
C310 22P
C311 22P
C312 22P
C313 22P
C314 22P
P110
NC
44
43
42
41
40
39
38
37
36
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
45
35
ODCK
GND
DE
GND
VSYNC
GND
HSYNC
GND
NC
BO-7
BO-6
BO-5
BO-4
GND
BO-3
BO-2
BO-1
BO-0
GND
GO-7
GO-6
GO-5
GO-4
GND
GO-3
GO-2
GO-1
GO-0
GND
RO-7
RO-6
RO-5
RO-4
GND
RO-3
RO-2
RO-1
RO-0
PVDD
PVDD
TEST
TEST
TEST
GND
GND
C315 22P
P111
NC
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
GND
BE-7
BE-6
BE-5
BE-4
GND
BE-3
BE-2
BE-1
BE-0
GND
GE-7
GE-6
GE-5
GE-4
GND
GE-3
GE-2
GE-1
GE-0
GND
RE-7
RE-6
RE-5
RE-4
GND
RE-3
RE-2
RE-1
RE-0
C316 22P
C317 22P
C318 22P
C319 22P
C320 22P
C321 22P
C322 22P
C323 22P
C324 22P
ViewSonic Corporation 14 Confidential – Do Not Copy
VA720-1
VE175/b
I803
F801
R802
6.8. AC-DC POWER
PE
T801
ERL-28
1
6
5
3
9
12
7,8
10,11
L805
ET-24
D813 2A07
D812 2A07
D811 2A07
P801
AC IN 100-240V
N
L
D807
15V
I801 KA1M0565R
32
14
Vcc DRAIN
GND FB
R801 1M 0.5W
D810 2A07
D804 FCH20A15
I802
TLP721F
4
3
1
2
C802
4700PF
L801
JUMPER
+
C813
3300UF/16V
C824
0.22UF
C801
0.22UF
C803
4700PF
L803
JUMPER
P802
1
2
3
4
5
P803
NC
1
2
3
4
5
6
7
8
9
R840 10
D814
NC
+
C812
100UF 400V
C806
0.22UF 630V
R805
150K 1W
D802
HER157G
R806
150K 1W
L802
BEAD
R804
180K 3W
+
C818
NC
D803 UF4004
R816 10
+
C819
NC
+
C808
100UF/50V C809
0.1UF
D805 NC
C822 NC
L804
5UH
R809 NC
+
C816
1000UF/16V
+
C817
NC
C823
4700PF
2.5A/250V
+
C811
NC
R808
NC
C810
0.033UF/50V MEF R807
16.2K 1%
C820
0.1UF/50V MEF
R815
120
R813 100
R812
4.87K 1%
R811
19.1K 1% R810
NC
NC
TL431D
C815
100PF NPO
L807 NC
ViewSonic Corporation 15 Confidential – Do Not Copy
VA720-1
VE175/b
7. THEORY OF OPERATION
7. WORKING THEOREM
A. DC-DC CONVERTER
! "# $%&' ()* "+,-&' "#-&'
!-
-"# $%& )-./
0)1(2)
2)22
B. A/D converter
3*!45+)
3*$66326,- 22/
45+'7)(( ,- (
)+)-- /(6-8-,9:/
3 2 ( 2( !#3
(22))
:0;<! 1( 8
!=302((/):0;<!
1(
!#3 2(2)2
5<*'
)*))'3*$663())
2'2
C. Scaling controller
!2530>530>53
)
0*-? ( @= ( (2
2 *43 2 ' 86% 2 (
22(
% 2 2/ 86% 2 )
"2' ' A34' @= ' & 0 "4&
%, 1 ) ' 5 )
22('222/(
5()6 8@
('$ 8@
,6':('('*B'5!#.
3A>=< ( ' #!*=<
0- *0
' +.#=< @
%,!
0*-0*---!
0>53C#!*23#!*245+
22'82!4
22#!*22
!42
45+2(863@*'
,6 45+ 0*- C '
ViewSonic Corporation 16
Confidential – Do Not Copy
VA720-1
VE175/b
This manual suits for next models
2
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