Oki ML390 Service Manual page 70

All
This part is found in the Microline 390, Microline 391, Microline 390-Plus, and Microline 391-Plus printers.
Compatibility - Microline 390/391 vs. Microline 390/391-Plus
The differences between the Microline 390/391 and Microline 390/391-Plus printers are listed below.
Hardware Differences
· Operator Panel
· Operator Board
· Character Generator Programmable Read Only Memory (CGROM)
· Programmable Read Only Memory (PROM)
· Middle Cover
Operational Differences
· "Plus" printers have more resident fonts.
· In the "Plus" printers, data in the receive buffer is printed upon receipt, without having to wait for a line
terminator character (CR/LF or FF).
· In the "Plus" printers, the DC1/DC3 Acknowledge/Ignore, Receive Buffer Size, and RESET inhibit can be
controlled through the printers Menu.
Serial Number Revision Levels
Microline 390/391
A
Rev A units are original production units. An interconnect module connects the power supply board to the
main control board.
B
Rev B units are retrofitted to include a modified interconnect module, which prevents corrosion.
C
These units have a cable connection between the power supply board and the main control board. The
cable connection wire replaces the interconnect module.
Microline 390/391-Plus
Revision levels do NOT apply to the "Plus" printers.
NOTE:
Please refer to the parts lists for parts differentiation. Please be sure of the parts you need before ordering
to avoid confusion and incorrect parts orders.
Printer Serial Number Identification
There are three serial number revision levels for the printers. Hardware differences exist between levels.
To identify the revision level of a printer, record the serial number from the back of the printer. Refer to the
following to decode the serial number.
Example Printer Serial Number: 401A0154693
Date Code 401 (4 = year. 01 = month)
Revision A