HP LaserJet 3050 - Page 8

Printer (product base) functions ......................................................................................................... 74
Engine control system (engine control unit and power-supply assembly) ......................... 75
Print-engine control system ............................................................................... 75
Printer (product base) laser/scanner ................................................................. 76
Power system on the power-supply assembly .................................................. 77
Ac power distribution ........................................................................ 77
Dc power distribution ........................................................................ 77
Overcurrent/overvoltage ................................................................... 77
High-voltage power distribution ........................................................ 78
Image-formation system .................................................................................................... 79
The seven image-formation processes ............................................................ 79
Print cartridge .................................................................................................................... 80
Printer (product base) paper-feed system ......................................................................... 80
Jam detection in the all-in-one .......................................................................................... 82
Conditions of jam detection ............................................................................... 82
HP LaserJet 3050 all-in-one unique components .............................................................................. 83
Basic operation .................................................................................................................. 83
ADF pickup-and-feed system ............................................................................ 85
Optical scanning system ................................................................................... 87
HP LaserJet 3052/3055 all-in-one unique components ..................................................................... 89
Scanner and ADF functions and operation ........................................................................ 89
Scanner functions ............................................................................................ 89
Scanner operation ............................................................................................. 90
ADF operation ................................................................................................... 90
ADF paper path and ADF sensors .................................................................... 91
ADF jam detection ............................................................................................. 91
Fax functions and operation (HP LaserJet 3050 all-in-one and HP LaserJet 3055 all-in-one
only) .................................................................................................................................................... 92
Computer and network security features ........................................................................... 92
PSTN operation ................................................................................................................. 92
Distinctive ring function ...................................................................................................... 93
Faxing with Voice over IP services .................................................................................... 94
The fax subsystem ............................................................................................................. 94
Formatter in the fax subsystem ......................................................................................... 94
LIU in the fax subsystem ................................................................................................... 95
Safety isolation .................................................................................................. 95
Safety-protection circuitry .................................................................................. 95
Data path ........................................................................................................... 96
Hook state ......................................................................................................... 96
Downstream current detection .......................................................................... 96
Hook switch control ........................................................................................... 97
Ring detect ........................................................................................................ 97
Line-current control ........................................................................................... 97
Billing- (metering-) tone filters ........................................................................... 97
Fax page storage in flash memory .................................................................................... 98
Stored fax pages ............................................................................................... 98
Advantages of flash-memory storage .............................................................. 98
5 Removal and replacement
Removal and replacement strategy .................................................................................................. 100
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