Genicom MatrixPrinter LA36 User Manual

Page 106

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The LA36N/LA36W controller (Figure 5.17) consists of an printed circuit board, called the printer control board

or the main board with ROM. The MPU controls operation under control of programs in ROM.

(1) Printer control board (ROM board)

The printer control board governs the interface, memory, and mechanism. It is also called ROM board. The

name on the Recommended Spare Parts List is “main board with ROM”.


The LA36N/LA36W provides two types of interface –– Centronics parallel and RS-423 serial. Interface drivers

and receivers convert signals voltage levels.


The controller consists mainly of the MB90706, alarm detector (voltage comparator), and reset controller. The

MB90706 controls interface communication with the computer and memory devices, RAM, ROM, motor

drivers, and print head pin magnet drivers (Figures 5.20 and 5.21).


Memory consists of program ROM, character generator (CG) ROM, RAM, and EEPROM.


Drivers include print head and motor drivers and an alarm detector (voltage comparator). The print head and

motor drivers increase power, and supply it to the print head, the carriage motor, the paper feed motor, and the

optional ribbon shift motor.

Alarm detector:

The alarm detector checks the level of +34 V for each driver and the temperature of the print head.

(2) Power supply unit

The power supply unit supplies power to logic and driver circuits on the printer control board.

(3) Sensors

Sensors (phototransistors and a microswitch) detect status of the printing mechanism such as left-end position of

the carriage, paper presence on the platen, setting position of the paper select lever, and installation of options.

(4) Control panel

The control panel –– (7 push-buttons, 16 LEDs, a buzzer, and a control LSI) enables the user to communicate

with the printer.