ViewSonic VA912-4 Service Manual page 69

D32 R165
NC/ 1N4148 NC/100K/6
Q20
2
3AVCC1
3AVCC1
R147
4.7K/6
RESET
VCPU
C75
0.1U/6
U8
1 8
A0 VCC
2 7
A1 WP
3 6
A2 SCK
4 5
VSS SI
24LC16
PARAMETER
EEPROM
VCPU
R170 R171 R172
4.7K/6
4.7K/6 4.7K/6
ViewSonic Corporation
Reset circuit
VCPU
NC/2N3906
VCPU
R106
NC/82K/6
D33
R166
0/6 NC/DAN202U
C87 10pF/6
Y2
11.0592MHz
C88 10pF/6
R80 R81 R179
VCPU
KEY1
2K/6
2K/6 2K/6
R142 NC
WP_EE
R83 100/6
IICSCL
R92 100/6
IICSDA
LED_R
LED_G
R180
PANEL_PW12
MUTE KEY2
NC
KEY3
STBY
PWR_SEL
VCC12
R41
6.8K/6
KEY1
R38
2K/6
KEY2
KEY3
2004/12/28
Confidential - Do Not Copy
66
3DVCC
C
3DVCC
R79
R78
B
10K/6
10K/6
Q12
LED_G R82 4.7K/6 2N3906
2
Q13
R93 4.7K/6
LED_R
2
2N3906
MENU
SEL
PWR
VCPU DOWN
UP
RIGHT
LEFT
C84 C85
+
Junction from
22uF/16V 0.1u/6
A change to B
VCPU
R163
4.7K/6
I1 R164 22
3
P5.0
2
P5.1
12 1
P5.2
X1
42
P5.3
41
P5.4
40
11
X2 P5.5
34
P5.6
39 R39
7
RESET DA8/HLFHO
38 R40
DA9/HALFV
17
P1.0
R181 22
18
P1.1
20
19
INT0/P3.2 P1.2
21
P1.3
22
P1.4
14
23
ISCL/P3.5/T1 P1.5
13 24
ISDA/P3.4/T0 P1.6
27
25
P6.0/AD0 P1.7
26 35
P6.1/AD1 DA7
16 36
P6.2 P4.0
9 37
P6.3 P4.1
30 15
P6.4 P4.2
31
P6.5
28
32
P6.6 P3.1/TXD
33 29
P6.7 P3.0/RXD
MTV312M64
KEY1
KEY2
KEY3
VA912-4_VA912b-4
E
3DVCC
less R94 to CN6 pin 11
R101,R103 net swap
R95 1K/6
R96 1K/6
R97 1K/6
R98 1K/6
R99 1K/6
R100 1K/6
R101 1K/6
R102 220/6
R103 220/6
TO BUTTON BOARD
VCPU
VCPU
AVS
MENU
SEL
R110 R111 R112 R113
PWR
UP
4.7K/6 4.7K/6 NC NC 4.7K/6
DOWN
RIGHT
LEFT
4.7K/6
4.7K/6
VRMT
WP_EE
VCPU
R124 100/6
TxD
R125 100/6
RxD
R109 4.7K/6
R108 4.7K/6
JP3
2004/12/28
CN6
10
9
8
7
6
5
4
3
2
90° E&T
1
4607-11Pin
4501-10-10P-R
R114 R115
4.7K/6
SDIO1
SDIO2
SDIO3
RTD_SCLK
RTD_SCSB
JP1
1
DDC_SDA
DDC_SCL 2
3
4
5DVCC
HEADER 4
ViewSonic Corporation
MCU & BUTTON
Model
Title
Date Rev: