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III –
24
3.4
NCU PCB
The NCU PCB switches the communications line to telephone or built-in MODEM, under the
control of the main PCB.
NCU PCB Circuit Diagram (U.S.A. versions)
1
Surge absorber
2
Noise filters
3
Line relay (CML relay)
4
Line transformer
5
Circuit related to the line transformer
6
High-impedance transformer circuit
7
Calling signal detector
8
Loop current detector
9
Dial pulse generator
:
Telephone circuit
A
Reference voltage generation circuit for the operational amplifier in
⑤
.
1 2
3
4
5
6
7
8
9
:
2
2
A
Summary of Contents for MFC 4550
Page 5: ...CHAPTER I GENERAL DESCRIPTION ...
Page 14: ...CHAPTER II INSTALLATION ...
Page 15: ...CONTENTS 1 INSTALLING THE UPDATE DATA TO THE FACSIMILE EQUIPMENT II 1 ...
Page 18: ...CHAPTER III THEORY OF OPERATION ...
Page 49: ...CHAPTER IV DISASSEMBLY REASSEMBLY AND LUBRICATION ...
Page 81: ...CHAPTER V MAINTENANCE MODE ...
Page 89: ...V 7 Scanning Compensation Data List 200 dpi ...
Page 133: ...CHAPTER VI ERROR INDICATION AND TROUBLESHOOTING ...
Page 163: ...MAIN 8 8 FAX3550 3650 8000P 8200P MFC4550 6550MC 7550MC MFC9000 9500 A ...
Page 185: ...D CONTROL PANEL 1 2 ...
Page 187: ...E POWER SUPPLY 120 V Low voltage power supply ...
Page 188: ...E POWER SUPPLY 200 240 V Low voltage power supply European versions ...
Page 189: ...E POWER SUPPLY 200 240 V Low voltage power supply Asian versions ...
Page 190: ...E POWER SUPPLY High voltage power supply ...
Page 191: ...Sept 98 5X52012 Printed in Japan ...