Chapter Iii Electrical System; Main Pcb; Outline - Brother 1660E Service Manual

CHAPTER III ELECTRICAL SYSTEM

Electric signal levels are expressed by "High" (approximate the supply voltage) or "Low"
(approximate 0V). Signals with hyphen or slash, such as -FSRD or FSRD/, are low-active and
signals without hyphen or slash, such as FSRD, are high-active signals.

1. MAIN PCB

1.1 Outline

The Main PCB consists of the Video Controller Circuit and the Engine Controller Circuit.
The Video Controller Circuit performs the following functions.
(1) Converts data received from an external device, such as a personal computer, through
Centronics parallel interface or RS-232C serial interface into video data and transfers it
to the Engine controller circuit.
(2) Displays the current printer status in LED and LCD, and enables settings from the control
panel.
The operation sequence of the printer controlled by a microprocessor in the Engine Controller
Circuit. The Engine Controller Circuit outputs signals to drive the various loads on the laser
diode, scanner motor, main motor, etc. according to the print commands and image data from
the external device.
CDCC (bolse) IF
PC
RS-232C IF
PC
FONT
CARTRIDGE
IC CARD
(PCMCIA)
Video controller
ASIC
MB87F1610
+24V
Regurator
MIO RELAY
MIO BOARD (CONNECTOR)
PCB
Engine controller
Figure 3.1 Main PCB Block Diagram
Main PCB
Main CPU
MB86832
MASK ROM
32M mask 2 4MB
DRAM
16M 4 8MB
DRAM (SIMM 2 slots)
64MBmax.
EEPROM
24CO4 4Kbit
Gate Array
µPD65632GF-
(IO PORT. ENGINE)
Engine CPU
M38063
III - 1
CONTROL PANEL
+24V
+5V Low-voltage
GND Power Supply