Brother International HL 1240 Service Manual - Page 52

CHAPTER 3 THEORY OF OPERATION 1.3.8 Engine I/O HL-1240 Fig. 3-17 shows the engine interface circuit. The interface with the engine PCB is by fullduplex synchronous serial method. Fig. 3-17 HL-1250 Fig. 3-18 shows the engine interface circuit. The interface with the engine PCB is by fullduplex synchronous serial method. Fig. 3-18 1.4 Engine PCB The gate array which transforms the serial signal from the main PCB into the parallel signal is mounted on the engine PCB. The engine PCB controls the following parts by using the transferred signal data; Main motor Toner sensor Panel PCB Cover sensor Fan motor Front registration sensor Thermistor Rear registration sensor Polygon motor Upper paper cassette sensor (HL-1250 only) Solenoid Lower paper cassette registration sensor (HL-1250 only) High-voltage power supply 3-14