- HP Laserjet Enterprise CP4020/CP4520 Manual

Step 6: Secondary transfer ............................................................................... 26
Step 7: Separation ............................................................................................ 27
Step 8: Fusing ................................................................................................... 27
Step 9: ITB cleaning .......................................................................................... 28
Step 10: Drum cleaning ..................................................................................... 28
Print cartridge .................................................................................................................... 28
Developing-roller engagement and disengagement .......................................................... 30
Intermediate transfer belt (ITB) unit ................................................................................... 31
Primary-transfer-roller engagement and disengagement .................................. 32
ITB cleaning ...................................................................................................... 34
Calibration .......................................................................................................................... 34
Color-misregistration control ............................................................................. 35
Image-stabilization control ................................................................................ 35
Pickup, feed, and delivery system ...................................................................................................... 37
Pickup-and-feed unit .......................................................................................................... 41
Cassette pickup ................................................................................................. 41
Cassette-presence detection ............................................................ 42
Cassette lift operation and cassette paper-presence detection ........ 43
Cassette multiple-feed prevention .................................................... 43
Multipurpose tray pickup ................................................................................... 44
Paper feed ......................................................................................................... 45
Skew-feed prevention ....................................................................... 46
Paper detection ................................................................................ 47
Feed speed control ........................................................................... 48
Fusing and delivery unit ..................................................................................................... 48
Loop control ...................................................................................................... 49
Pressure-roller pressurization control ............................................................... 50
Duplexing unit (HP Color LaserJet CP4525dn, HP Color LaserJet CP4025dn, and HP
Color LaserJet CP4525xh only) ......................................................................................... 52
Duplexing reverse and feed control .................................................................. 52
Duplex print operation ....................................................................................... 53
Jam detection ..................................................................................................................................... 55
Optional paper feeder ......................................................................................................................... 57
Motor control ...................................................................................................................... 59
Paper-feeder pickup and feed operation ........................................................................... 60
Paper-size detection and cassette-presence detection ..................................................... 62
Paper-feeder cassette lift operation ................................................................................... 63
Paper feeder jam detection ................................................................................................ 64
2 Removal and replacement
Introduction ......................................................................................................................................... 68
Removal and replacement strategy ................................................................................................... 68
Electrostatic discharge ....................................................................................................................... 69
Required tools ................................................................................................................................... 69
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