Brother PT-2500PC Service Manual page 50

CHAPTER III ELECTRONICS
3.1 OUTLINE OF CONTROL ELECTRONICS .......................................................................................III-1
3.1.1 Main PCB...........................................................................................................................III-1
3.1.2 Power Supply PCB.............................................................................................................III-1
3.1.3 Sensor PCB .......................................................................................................................III-2
3.1.4 Tape End Sensor PCB .......................................................................................................III-2
3.1.5 Sub PCB ............................................................................................................................III-2
3.1.6 Cutter Sensor .....................................................................................................................III-2
3.1.7 Cutter Motor .......................................................................................................................III-2
3.1.8 Tape Feed Motor................................................................................................................III-2
3.1.9 Thermal Head ....................................................................................................................III-2
3.2 MAIN PCB .......................................................................................................................................III-3
3.2.1 Logic Components .............................................................................................................III-4
[1] CPU (M30622M8)............................................................................................................III-4
[2] RAM (SRAM) ..................................................................................................................III-4
[3] ROM (EEPROM).............................................................................................................III-4
3.2.2 Solder Points......................................................................................................................III-4
3.2.3 Logic and VH Power, and Related Circuits .........................................................................III-5
3.2.4 Tape Feed Motor Drive Circuit ...........................................................................................III-6
3.2.5 Cutter Motor Drive Circuit...................................................................................................III-7
[1] Circuit operation ..............................................................................................................III-8
[2] Error processing ..............................................................................................................III-8
3.2.6 Cassette Sensor Circuit ......................................................................................................III-9
3.2.7 Thermal Head Control Circuit ...........................................................................................III-10
3.2.8 Head Voltage Detection Circuit and Ambient Temperature Detection Circuit ....................III-11
3.2.9 Oscillation Circuit .............................................................................................................III-12
3.2.10 Tape End Sensor Circuit ..................................................................................................III-12
3.2.11 Switches & LEDs Circuit...................................................................................................III-13
3.2.12 Cover Open Sensor Circuit...............................................................................................III-13
3.2.13 Reset Circuit ....................................................................................................................III-14
3.3 POWER SUPPLY PCB..................................................................................................................III-15
3.3.1 +12V Power Supply Circuit...............................................................................................III-15
3.3.2 +5V Power Supply Circuit.................................................................................................III-16
3.3.3 DC Jack-related Circuit ....................................................................................................III-16
3.3.4 Interface Circuit................................................................................................................III-17
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