Brother FAX255 Service Manual page 30

3.2 Main PCB
The main PCB, which is the nucleus controlling the entire operation of the equipment, con-
sists of a FAX engine (ASIC), memories, MODEM, motor drive circuitry, sensor detection cir-
cuitry, and analog circuits for scanning, recording, and power transmission shifting.
NCU
Power
supply
Speaker
Mic**
Automatic
cutter
ROM
2
E PROM
SRAM *
DRAM **
engine
(ASIC)
2
E PROM: Electrically Erasable Programmable Read-only Memory
* Provided on the FAX255/FAX275/FAX-515/HOMEFAX3
** Provided on the FAX355MC/FAX375MC/FAX-525DT/FAX-525MC
Block Diagram of Main PCB
III – 18
FAX
Motor
driver
Sensors
Control panel
Recording head
CIS
Motor
Ni-MH
battery **
PCI**