
2.2 Main Control PCB
The main control PCB controls the operations of all machine functions.
Jumper JP2 on the main control PCB is used for battery back up of the SDRAM. Removing JP2 will
initialize the SDRAM. If the power is turned off, the battery will provide up to 72 hours (8MB) of back up
when fully charged.
Jumper JP1 on the main control PCB is used for battery back up of the SRAM. All user programmed data
and internal memory switch settings are held in SRAM. Removing JP1 will initialize the SRAM.
If the power is turned off, the battery will provide up to five years of back up when fully charged.
NOTE: JP1, JP2 should remain in the "ON" position at all times.
Memory (FLASH MEMORY, SRAM, SDRAM)
FLASH MEMORY --- T h e F L A S H M E M O R Y c o n t a i n s a l l p r o g r a m i n s t r u c t i o n s f o r u n i t operation.
SRAM --- T h e S R A M , w h i c h i s b a c k e d - u p b y a l i t h i u m b a t t e r y i s u s e d t o s t o r e u s e r p r o g r a m m e d
information.
SDRAM --- T h e S D R A M i s u s e d f o r b u f f e r , w h i c h i s b a c k e d - u p b y a b a t t e r y i s u s e d t o s t o r e m e m o r i z e d
documents.
NOTE: The SDRAM back-up battery is connected to the PCB MAIN. When the PCB MAIN is replaced,
the connection will be lost. Therefore, please reenter the date and time, after you have replaced
the PCB MAIN. (Press MENU, 2, 1, 0, 9, and enter month, then day, year, hour and minute in 24-
hour format.)
NOTE: Turning parameters for Color(R,G,B) and Gray mode are stored in the EEPROM(IC42). When the
PCB MAIN is replaced, the EEPROM on malfunction PCB should be replaced to the new PCB.
FBS
MOTOR
ADF
MOTOR
NCU PCB
TONE RXA TXA
DISPLAY
KEY
PA NE L
G/A
PNAEL PCB
MODEM
MONITOR
CONTROL
CPU
USB
SRAM
SDRAM
SDRAM
Ni-MH
H.V.POWER
SUPPLY UNIT
AC
PRINTER
CONTROL
MOTOR
CONTROL
IMAGE
PROCESS
CCD
SDRAM
INVERTERCCFL
CCD PCB
+24V,
+24V,
+5V,+3.3V
MAIN CONTROL PCB
CENECTOR-B PCB
Extention Memory
Lithium
+24V
+24V,+12V,AREF
FLASH
MEMORY
POWER SUPPLY
UNIT
PRINTER
UNIT
MFP
ENGINE
Main control PCB block diagram
2-3
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