Chapter 2 Electrical Theory; System Configuration; Main Pcb (Printed Circuit Board); Switch Pcb (Printed Circuit Board) - Brother DP-525CJ Service Manual

SERVICE MANUAL
CHAPTER 2 ELECTRICAL THEORY
1.

System Configuration

The major electronic component parts of the machine are shown in Fig. 2.1.
1.1.

Main PCB (Printed Circuit Board)

The main PCB controls the entire system including the LCD, ink cartridge, and the
motors in the printer.
The motors and the ink cartridge are driven by +24 VDC, and the CPU and other
devices are driven by +5 VDC.
1.2.

Switch PCB (Printed Circuit Board)

Receiving power from the AC adaptor, the switch PCB supplies voltage to the main
PCB, through the power switch and the fuse.
1.3.

Keyboard FPC (Flexible Printed Circuit)

The keyboard FPC has electrodes arranged in a matrix circuit pattern. The keyboard
status is sent from the FPC to the main PCB.
1.4.

FDD (Floppy Disk Drive) Module

The FDD can read and write information supplied to the main PCB. The FDD is driven
by +5 VDC.
1.5. LCD (Liquid Crystal Display) Module
The LCD PCB contains the driver for the dot matrix of the LCD on which various
information is displayed. The CFL backlight (Models: DP-550, LW-810icBL, and LW-
840ic) is driven by +5 VDC from the main PCB.
2-1
THEORY
Electrical