ELCOM Euro-500T Handy, Service Manual

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© Elcom Ltd.
Service manual
3
Euro-500T Handy
Table of contents
1 INTRODUCTION ............................................................................................................................ 5
1.1 Euro-500T Handy cash register technical parameters ............................................................ 5
1.2 System configuration ................................................................................................................. 5
1.3 Cash register block diagram...................................................................................................... 5
2 CIRCUIT SCHEMES AND FUNCTIONS ........................................................................................ 6
2.1 Connection circuits .................................................................................................................... 6
2.1.1 External power supply ..................................................................................................... ............. 6
2.1.2 Primary connection circuit ............................................................................................................ 6
2.1.3 Voltage stabilizer .......................................................................................................................... 7
2.1.4 Printer connection circuit .............................................................................................................. 8
2.1.5 Secondary connection circuit ....................................................................................................... 8
2.1.6 Circuit for connecting the fiscal memory ....................................................................................... 9
2.1.7 Power supplies characterisation ................................................................................................... 9
2.2 Micro-controller and its support circuits ................................................................................ 10
2.2.1 E-500N micro-controller ............................................................................................................. 10
2.2.2 Memory circuits .......................................................................................................................... 12
2.2.3 System start and outage ............................................................................................................ 13
2.2.4 Current time circuit ..................................................................................................................... 13
2.3 Input-Output circuits ................................................................................................................. 14
2.3.1 Print control circuits .................................................................................................................... 14
2.3.2 Keyboard .................................................................................................................................... 16
2.3.3 Displays ..................................................................................................................................... 17
2.3.4 Communication circuits .............................................................................................................. 20
2.3.5 Interconnection of FM circuits ..................................................................................................... 21
2.3.6 Other circuits ............................................................................................................................. 22
3 THE MLT-288 THERMAL PRINTER ............................................................................................ 24
3.1 Basic layout ............................................................................................................................... 24
3.2 Thermal head ............................................................................................................................ 24
3.2.1 Thermal head composition ......................................................................................................... 24
3.2.2 Thermal head data processing ................................................................................................... 25
3.2.3 Print data and their position ........................................................................................................ 25
3.2.4 Thermistor layout ....................................................................................................................... 25
3.2.5 Time chart .................................................................................................................................. 25
3.3 Paper shifting ............................................................................................................................ 26
3.3.1 Stepping motor layout ................................................................................................................. 26
3.3.2 Excitation sequence ................................................................................................................... 26
3.3.3 Control circuit ............................................................................................................................. 26
3.4 Sensor of head position ........................................................................................................... 27
3.5 Sensors of paper ribbon end ................................................................................................... 27
3.6 Overall time chart ...................................................................................................................... 27
3.7 Printer connectors .................................................................................................................... 28
3.7.1 Thermal head connector ............................................................................................................ 28
3.7.2 Motor and sensors terminal ........................................................................................................ 29
3.8 How to clean thermal head ...................................................................................................... 29
4 MODULE (RE)INSTALLATION .................................................................................................... 30
4.1 Dismantling the cash register .................................................................................................. 30
4.2 Accumulator replacement ........................................................................................................ 32
4.3 Printer replacement .................................................................................................................. 33
4.4 Motor replacement .................................................................................................................... 34
4.5 Electronics mainboard replacement ....................................................................................... 35
4.6 EPROM replacement ................................................................................................................ 36
4.7 Replacement of damaged SRAM or replacement of SRAM with higher capacity .............. 36