OKIDATA OF2200, Service Manual

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Page: 153
Service Guide OF2200/2400/2600
Chapter A Board Diagrams
A.2.02 Main Control Board (DFCU) Okifax 2400/2600
Function
The main control board contains an IC that provides voice answering in the TEL/FAX Mode in accordance
with the INPUT/OUTPUT Gate Array and the microprocessor. This board converts parallel send data to
serial data, converts serial receive data to parallel data,
modulates/demodulates data, and generates multi-frequency signals for tone dialing. It amplifies signals
and sends the amplified signals to a speaker. The main control board houses an 8 MHz Microprocessor,
static RAM, ENCODER/DECODER, and a modem IC. This board also monitors the status of the PC1,
PC2, B4, and A3 photosensors.
Firmware
NONE
Fuses
NONE
Jumpers
NONE
Sensors
NONE
Switches
NONE
Test Points
CN 5 Pin 1: GROUND
CN 5 Pin 13: +5 vdc
CN 5 Pin 14: +12 vdc
CN 5 Pin 15: -12 vdc
CN 12 Pin 2, 5, 8, 11: +5 vdc