Samsung sf150t Service Manual

Also see for SF-150T: Operator's guide

Contents

5-2-12 Motor ControllerThis facsimile machine perform sending, receving,and printing functions utilising a single 24 voltmotor with a 120 ohm winding resistance.Four drive strobe pulses operate the motor.5-2-13 Serial communication SignalsThe KS16118 have two full-duplex serialcommunication port.One port is used for I-LIU communication on LIUPBA, and is a standart UART (UniversalAsynchronous Receiver/Transmitter).Another port, not used, may be configured forUART or SRT (SynchronousReceiver/Transmitter) operation.5-2-14 ResetTo initialize the chip’s internal logic, the resetinput (/RESET) must be held to 0 Volt for at least22 CPU clocks. During this time, Vdd must begreater than 3 Volt.The watchdog timer can also invoke a systemreset.When the reset input is released, the resetcondition continues for about 209.7 ms.While the KS16118 is in this state, 0 Volt is appliedto the /RSTOUT pin.[ +5V Power Monitoring ]If 5 volt power to MX93000AFC’s pin 6 (VPOW)drops to between 4.6V and 4.4V (typically 4.5V),power failure is indicated and the output ofMX93000AFC’s pin 5 (/POWB) will go `low’(GND5).This causes the KS16118 to become active (low=reset).The KS16118 reset causes the /REST0 terminal to bereset.Circuit Description5-6 SF150TTable 5-1: Motor FunctionsMotor FunctionSwing Gear ControlDocument Out100 pps100ppsDrive Strobe Pulse Phase22Other 100pps 2Super Fine Mode 100pps 1-25-3 MemorySystem memory consists of 128 kB EP-ROM and 32 kB SRAM. All of SRAM is backed up.ROM and SRAM are selected by chip select lines, and data is accessed by the units position of the byte.ROM has two banks. One Bank is as low bank that address range is 0100H-FFFFH.Another bank is as high bank 10000H-1FFFFH. ROM’s bank is selected port 0 (bit 0) of the KS16118.5V power is applied to SRAM through VB. This model facsimile machine uses a Lithium battery.A 1 kohm resistor in series with the positive battery terminal is for battery protection.5-4 CODEC circuit with Modem-TX and RX signal pathThis has PCB CODEC which has ablity that converts voice signal to A/D and is able to store is DRAM and convertto voice signal passing through D/A transmission after scanning from voice digital stored in DRAM by DSP.This has PRE-PGA(Programmable Gain Amplifier) that is able to amplift selectively among Mic input, remotsignal, rx signal.This has ALC(Automatic Level Control) circuit has maximum 42dB gain to be convenient for recording using Mic.This have two comparator having 1.25V reference voltage and two universal opamp.This has 1 W speaker drive amplifir that is able to drive 8 ohm speaker.Because MX93000AFC’s control uses synchronous communication port, that is fast in action is convenient.