Oki ML490 Maintenance Manual page 115

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
Is +12V, -8V supplied on Control Board?
Yes No
Remove RS232C I/F Board
Is the +12V, -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
42114101 Rev.1
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
+12V (pin3)
20 CN2
0V (pin8) -8V (pin1)
1
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