2A3/4
2-3-19
( 4 ) Reset circuit
+5 V DC
3
8
1
6
5
4
CK
RES
CT
VREF
50
7
CPU
IC7
Vcc
GND
RES
2
1
C7
2
VS
IC1
GROUND
GROUND
1
+
C17
R23 2
1
2
1
7
C2
2
2
1
C1
+5 V DC
1
R2
2
+5 V DC
R1
Figure 2-3-15 Reset circuit
V
CC
V
SH
V
SL
0.8 V DC
C
K
C
T
RES
T
CK
B
A
Figure 2-3-16 CPU reset operation timing chart (abridged)
IC1 monitors the supply voltage and also determines if the CPU IC7 is operating
correctly. If the supply voltage V
CC
drops below V
SL
(approx. 4.2 V DC), the reset signal
(RES) is output to the CPU IC7 (
A
in the timing chart).
IC1 monitors the clock signal (CK) from pin 50 of the CPU IC7 which goes low
periodically. If the CPU IC7 fails, IC1 detects that the clock signal (CK) has stopped and
sends a reset signal (RES) to the CPU IC7 (
B
in the timing chart). To reset the CPU
IC7, pin 8 (RES) of IC1, which usually outputs 5 V DC, goes low and takes the level at
pin 7 of the CPU IC7 low.
Содержание Ri 4230
Страница 1: ...4230 5230 S M MCA SERVICE MANUAL Published in June 00 2A370941 Revision 1 Ri 4230 5230 Ri 4230 5230 ...
Страница 3: ...SERVICE MANUAL Ri 4230 5230 ...
Страница 13: ...4230 5230 S M MCA THEORY AND CONSTRUCTION SECTION I I Theory and Construction Section ...
Страница 14: ...1 1 5 2A3 4 CONTENTS 1 1 Specifications 1 1 1 Specifications 1 1 1 ...
Страница 21: ...1 1 7 2A3 4 CONTENTS 1 2 Handling Precautions 1 2 1 Drum 1 2 1 1 2 2 Developer and toner 1 2 1 ...
Страница 100: ...4230 5230 S M MCA ELECTRICAL SECTION II II Electrical Section ...
Страница 119: ......
Страница 138: ......
Страница 159: ...4230 5230 S M MCA III Set Up and Adjustment Section III SET UP AND ADJUSTMENT SECTION ...
Страница 419: ...1 1 25 2A3 4 CONTENTS 3 5 Self Diagnosis 3 5 1 Self diagnosis 3 5 1 1 Self diagnostic function 3 5 1 ...
Страница 448: ...2A3 4 3 6 3 25 Toner scatters at the leading edge of the image See page 3 6 17 ...