Brother SC-2000, Service Manual

Page: 115 / 150

II - 1
CHAPTER II GENERALS
1. CONFIGURATION OF THE ELECTRONIC PART
Fig. 2.1 shows the configuration of the electronic part, which consists of seven
PCBs, two motors, and a thermal head.
PCBs Main PCB, power supply PCB, charge PCB, control panel PCB, size
detection PCB, reflective sensor assy, and transparent sensor assy.
Motors Main motor and paper feed motor.
2. ELECTRONIC PCB
(1) Main PCB
This PCB contains a 3-terminal regulator which stabilizes at +5V fluctuating DC
current 8V voltage supplied by the power supply PCB. It also assures
management of all of the following: LCD, motors, serial/parallel interfaces,
thermal head, keyboard inputs, EEPROM, reflective and transparent sensors,
charge/discharge, and size detection.
(2) Power supply PCB (100V or 200V system)
This PCB, equipped with a switching regulator, stabilizes at +8V and +25V
fluctuating AC current voltage, and supplies it to the main PCB.
(3) Main Capacitor Charge PCB
This PCB charges the capacitor at 330V in response to charge signals output
from the main PCB to cause the xenon tube to emit light, or forcibly discharges
the capacitor in response to power supply OFF or discharge signals.
(4) Control panel PCB
This PCB sets each mode by using the Mode and Set keys, and displays the
operation mode on the LCD.
(5) Size detection PCB
This PCB detects the size of a stamp. An error message appears when a
stamp inappropriate for the set draft sheet size is equipped.
(6) Reflective sensor assy
This PCB detects the ribbon, automatic feed position, and manual feed.
(7) Transparent sensor assy
This PCB detects the printing position and a trigger for light emission by the
xenon tube.