Samsung SF6500 Service Manual page 72

Circuit Description
5-2 OPE PBA
OPE board consists of Micom, LED, key matrix, document detect sensor, and scan position sensor. When a
user presses a key, the key input data is applies to Micom through the key matrix. Micom applies the
corresponding code to the main board through UART (Universal Asynchronous Receiver Transmitter). The
main board sends out the data from Micom to LCD or LED to display the information.
5-3 Mother PBA
This board supplies power from SMPS to other boards and connects signals from the main board to HVPS,
Scan, LSU, and mech boards.
5-4 HVPS PBA
This HVPS (High Voltage Power Supply) supplies -400 VDC bias voltage into the magnet roller, -1100 VDC
charging voltage into charging roller, 4000 VDC transfering voltage and -900 VDC retransfering voltage into
the transfer roller.
5-5 Scan PBA
This board consists of Scan motor drive IC (SLA7024M), CIS, and OPE PBA interface connector. It is
connected to the main board through the mother board.
5-6 Mech PBA
This board contains the main motor driver IC (SLA7020M), speaker, solenoid, and 2nd cassette connection
switch.
5-7 MFP PBA (Option)
This board controls PC interface function, such as PC printing, scanning, and PC faxing. It controls the data
signal between PC and this machine. This board contains 40-pin connector to connect to the main board, 36-
pin centronics connector to connect to PC, and CL-CD1283 chip, 74LS245, 74HC00 to perform IEEE-1284
operation.
Samsung Electronics 5-3