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42113901 Rev.2
131 /
Oki Data CONFIDENTIAL
No
Replace the Q2.
Yes Replace the Q3.
A
Yes Are ALE, PSEN, RD, WR, signals as specified in Figure C-6?
Figure C-7
542ns
180ns
271ns
542ns
5V
0V
5V
0V
5V
0V
ALE
PSEN
RD/WR
Figure C-6
ST bit
SP bit
5V
0V
5V
0V
RxD
SSD
No
Replace the Q3.
Yes Are (T1) SELECT and (INTO) BUSY signals low level?
No
Check Q3 on the Control Board.
Yes Are +9V and -9V input to Q1?
No
Replace defective component in +9/–9 volt control circuit.
Yes Is pin 1 SSD signal of Q3 High level?
No
Replace the Q3.
Yes Is pin 11 SSD of Q1 low level?
No
Replace the Q1 or the CN1?
Yes Is the RxD of Q3 as specified in Figure C-7?
Содержание ML421 Series
Страница 1: ...42113901 Rev 2 1 133 Oki Data CONFIDENTIAL ML420 421 PRINTER Maintenance Manual ODA...
Страница 2: ...42113901 Rev 2 2 Oki Data CONFIDENTIAL...
Страница 117: ...42113901 Rev 2 117 Oki Data CONFIDENTIAL Figure B 2 Printer General Assy 6 9 7 1 2 3 11 10 4 5 8...
Страница 122: ...42113901 Rev 2 122 Oki Data CONFIDENTIAL Figure B 4 Carriage Assy 12 9 8 6 14 4 10 7 11 13 3 1...