Service manual

CHAPTER 3 THEORY OF OPERATION
3-8
1.3.12 Video I/O
The video signal output from the ASIC is reversed through a transistor and output after being
corrected by the buffer IC.
1D
BDN
2D
VDON0
2D
ENBN0
VDD5
L7
0
VDD5
L6
0
R21
680
C22
C102
VDD5
R7
220k
R13
100
C27
C471
Q3
C3735
C
B
E
R8
1k
VDD3
R19
680
0V
0V
L5
0
0V
L3
0
L4
0
VDD3
R16
680
R15
330
1/10W
0V
0V
C21
C103
C18
C103
C23
C101
C20
C270
1
BD
CN1
5
DATA1
2
ENB1
3
+5V
4
GND
R10
0
R12
0
TP230
TP231
TP232
TP233
TP234 TP235
U2
TC7SH08FU
1
B
4
Y
5
VCC
2
A
3
GND
VDD3
R151
330
1/10W
Fig. 3-14
1.3.13 Scanner control
Fig. 3-15