Oki ML420 Maintenance Manual page 113

10-2 (RS232C I/F)
Is the correct cable used?
Yes No
Change I/F cable.
Is ALARM LED blinking?
No Yes
See tables 6.2 and 6.3 for the troubleshooting.
Make sure of the parameters for RS232C in the menu are correct.
Remedied?
No Yes
End
Are +12V and -8V supplied on Control Board?
Yes No
Remove RS232C I/F Board.
Are the +12V and -8V supplied on the Control Board?
No Yes
Replace RS232C I/F board.
Replace Control Board.
Replace RS232C I/F board.
Remedied?
No Yes
End
Replace Control Board.
42113901TH01 Rev.3
Baud rate
Bit length
Parity
Protocol
Busy signal and its polarity
Printer I/F pin assignment.
TXD 2 pin,
RXD 3 pin,
SSD 11 pin,
DTR 20 pin,
DSR 6 pin.
Control Board
20 CN2
0V (pin8) -8V (pin1)
Oki Data CONFIDENTIAL
+12V (pin3)
1
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