Brother P-touch 65 Service Manual page 36

CHAPTER III. ELECTRONICS
3.1 OUTLINE OF CONTROL ELECTRONICS ..........................................................................III-1
3.2 MAIN PCB...........................................................................................................................III-2
3.2.1 Block Diagram ........................................................................................................III-2
3.2.2 CPU........................................................................................................................III-3
3.2.3 LCD Controller........................................................................................................III-3
3.2.4 Key Contacts Matrix ...............................................................................................III-4
[ 1 ] Key contacts matrix................................................................................................III-4
[ 2 ] Solder points..........................................................................................................III-6
3.2.5 Power ON/OFF Key and Reset Circuit ...................................................................III-7
[ 1 ] Power ON/OFF circuit ............................................................................................III-7
[ 2 ] Automatic powering-off circuit................................................................................III-8
3.2.6 Motor Drive Circuit ..................................................................................................III-9
3.2.7 Thermal Head Drive Circuit ..................................................................................III-10
3.2.8 Voltage Detection Circuit ......................................................................................III-12
3.2.9 Oscillation Circuit..................................................................................................III-13
3.2.10 Power Supply Circuit ............................................................................................III-14
3.3 SUB PCB .........................................................................................................................III-15
3.3.1 Sub PCB ..............................................................................................................III-15
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