HP Laserjet P1560, P1600 service manual

4.5 (2)

LASERJET PROFESSIONAL P1560 and P1600

SERIES PRINTER

Service Manual

www.hp.com/support/ljp1560series

www.hp.com/support/ljp1600series

HP LaserJet Professional P1560 and

P1600 Series Printer

Service Manual

Development Company, L.P.

Reproduction, adaptation, or translation without prior written permission is prohibited, except as allowed under the copyright laws.

The information contained herein is subject to change without notice.

The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein.

Part number: CE663-90939

Edition 1, 4/2010

Trademark Credits

Microsoft®, Windows®, Windows® XP, and Windows Vista® are U.S. registered trademarks of Microsoft Corporation.

Conventions used in this guide

TIP: Tips provide helpful hints or shortcuts.

NOTE: Notes provide important information to explain a concept or to complete a task.

CAUTION: Cautions indicate procedures that you should follow to avoid losing data or damaging the product.

WARNING! Warnings alert you to specific procedures that you should follow to avoid personal injury, catastrophic loss of data, or extensive damage to the product.

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iv Conventions used in this guide

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Table of contents

1 Theory of operation ........................................................................................................................................	1
Basic operation .....................................................................................................................................	2
Major product systems .........................................................................................................	2
Product block diagram .........................................................................................................	2
Sequence of operation .........................................................................................................	3
Normal sequence of operation ............................................................................	3
Formatter-control system .....................................................................................................................	4
Sleep mode ..........................................................................................................................	4
Input/output ..........................................................................................................................	4
CPU .....................................................................................................................................	4
Memory ................................................................................................................................	4
Firmware .............................................................................................................	5
Memory use ........................................................................................................	5
PJL overview .......................................................................................................................	5
LEDM overview ....................................................................................................................	5
ACL overview .......................................................................................................................	5
Control panel .......................................................................................................................	6
Engine-control system ..........................................................................................................................	7
Motors, fans, clutches, solenoids, switches, and sensors ...................................................	8
DC controller operations ....................................................................................................	13
Fuser-control circuit ...........................................................................................................	15
Fuser failure detection .......................................................................................	16
Fuser temperature control .................................................................................	17
Fuser protective function ...................................................................................	18
Pressure roller cleaning ....................................................................................	18
Low-voltage power supply .................................................................................................	19
Overcurrent/overvoltage protection ...................................................................	20
High-voltage power supply ................................................................................................	21
Laser/scanner system ........................................................................................................	22
Laser failure detection .......................................................................................	23
Image-formation system .....................................................................................................................	24
Electrophotographic process .............................................................................................	24
Image formation process ...................................................................................................	26
Latent-image formation stage ...........................................................................	27

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Primary charging ..............................................................................	27
Laser beam exposure .......................................................................	27
Developing stage ..............................................................................................	28
Print cartridge ...................................................................................	28
Transfer stage ...................................................................................................	29
Fusing stage .....................................................................................	29
Cleaning stage ..................................................................................	30
Pickup, feed, and delivery system ......................................................................................................	31
Photo sensors and switches ..............................................................................................	32
Main-input tray or priority input slot ....................................................................................................	34
Jam detection ....................................................................................................................	34
2 Removal and replacement ...........................................................................................................................	35
Introduction .........................................................................................................................................	36
Removal and replacement strategy ...................................................................................................	36
Electrostatic discharge .......................................................................................................................	37
Required tools ...................................................................................................................................	37
Before performing service ..................................................................................................................	37
After performing service .....................................................................................................................	38
Post-service test .................................................................................................................................	38
Print-quality test .................................................................................................................	38
Parts removal order ............................................................................................................................	39
Pickup roller ........................................................................................................................................	40
Separation pad ...................................................................................................................................	41
Transfer roller .....................................................................................................................................	42
Covers ................................................................................................................................................	43
Main-input tray ...................................................................................................................	43
Output bin tray extension ...................................................................................................	44
Left cover, simplex product ................................................................................................	45
Remove the left cover, simplex product ............................................................	45
Left cover, duplex product .................................................................................................	47
Remove the left cover, duplex product ..............................................................	47
Right cover, simplex product .............................................................................................	50
Remove the right cover, simplex product ..........................................................	50
Right cover, duplex product ...............................................................................................	52
Remove the right cover, duplex product ...........................................................	52
Duplex door, duplex product ..............................................................................................	55
Duplex frame, duplex product ............................................................................................	56
Remove the duplex frame .................................................................................	56
Cartridge door ....................................................................................................................	57
Control panel .....................................................................................................................	59
Front cover .........................................................................................................................	61
Remove the front cover .....................................................................................	61

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Rear cover, simplex product ..............................................................................................	63
Remove the rear cover, simplex product ..........................................................	63
Face-down cover ...............................................................................................................	65
Remove the face-down cover ...........................................................................	65
Main assemblies .................................................................................................................................	67
Formatter PCA ...................................................................................................................	67
Laser/scanner assembly ....................................................................................................	68
Remove the laser/scanner assembly ................................................................	68
Reinstall the laser/scanner assembly ................................................................	71
Pickup assembly ................................................................................................................	72
Remove the pickup assembly ...........................................................................	72
Reinstall the pickup assembly ...........................................................................	78
Fuser ..................................................................................................................................	80
Remove the fuser ..............................................................................................	80
Reinstall the fuser .............................................................................................	86
Main motor .........................................................................................................................	87
Remove the main motor ....................................................................................	87
Reinstall the main-motor drive belt ....................................................................	92
Pickup solenoid ..................................................................................................................	93
Remove the pickup solenoid .............................................................................	93
Engine controller PCA .......................................................................................................	97
Remove the engine controller PCA ...................................................................	97
Reinstall the engine controller PCA ................................................................	102
Duplex-reverse solenoid, duplex product ........................................................................	104
Remove the duplex-reverse solenoid ..............................................................	104
Main fan, duplex product .................................................................................................	107
Remove the main fan ......................................................................................	107
Reinstall the main fan ......................................................................................	109
Duplex-connector PCA, duplex product ...........................................................................	110
Remove the duplex-connector PCA ................................................................	110
3 Solve problems ...........................................................................................................................................	113
Solve problems checklist ..................................................................................................................	114
Troubleshooting process ..................................................................................................................	116
Determine the problem source .......................................................................................	116
Power subsystem ............................................................................................................	117
Power-on checks .............................................................................................	117
Tools for troubleshooting ..................................................................................................................	118
Individual component diagnostics ....................................................................................	118
Engine diagnostics ..........................................................................................	118
Engine-test button ..........................................................................	118
Components tests ...........................................................................................	119
Drum rotation functional check ......................................................	119

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Half self-test functional check .........................................................	119
Diagrams .........................................................................................................................	120
Plug/jack locations ..........................................................................................	120
Location of connectors ....................................................................................	121
Locations of major components ......................................................................	122
General timing charts ......................................................................................	125
General circuit diagram ...................................................................................	126
Internal print-quality test pages ........................................................................................	127
Cleaning page .................................................................................................	127
Configuration page ..........................................................................................	127
Print-quality troubleshooting tools ....................................................................................	128
Repetitive defect ruler .....................................................................................	128
Interpret control-panel light patterns ................................................................................	128
Clear jams ........................................................................................................................................	133
Common causes of jams .................................................................................................	133
Jam locations ...................................................................................................................	133
Clear jams from the input trays ........................................................................................	134
Clear jams from the duplexer ...........................................................................................	136
Clear jams from the output areas ....................................................................................	138
Clear jams from inside the product ..................................................................................	139
Solve repeated jams ........................................................................................................	141
Change jam recovery ......................................................................................................	142
Solve paper-handling problems ........................................................................................................	143
Solve image-quality problems ..........................................................................................................	144
Image defect table ...........................................................................................................	144
Light print or faded ..........................................................................................	144
Toner specks ...................................................................................................	144
Dropouts ..........................................................................................................	145
Vertical lines ....................................................................................................	145
Gray background .............................................................................................	145
Toner smear ....................................................................................................	146
Loose toner .....................................................................................................	146
Vertical repetitive defects ................................................................................	146
Misformed characters ......................................................................................	146
Page skew .......................................................................................................	147
Curl or wave ....................................................................................................	147
Wrinkles or creases .........................................................................................	147
Toner scatter outline .......................................................................................	148
Moisture ..........................................................................................................	148
Change print density ........................................................................................................	149
Clean the product .............................................................................................................................	150
Clean the pickup roller .....................................................................................................	150
Clean the paper path .......................................................................................................	151
Clean the print-cartridge area ..........................................................................................	153

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Clean the exterior ............................................................................................................	154
Solve performance problems ...........................................................................................................	155
Solve connectivity problems .............................................................................................................	156
Solve direct-connect problems ........................................................................................	156
Solve network problems ..................................................................................................	156
Service mode functions ....................................................................................................................	158
Product resets ..................................................................................................................	158
Product updates ...............................................................................................................................	158
Firmware updates ............................................................................................................	158
4 Parts and diagrams .....................................................................................................................................	159
Order parts by authorized service providers ....................................................................................	160
Order replacement parts ..................................................................................................	160
Related documentation and software ..............................................................................	160
Supplies part numbers .....................................................................................................	160
Customer self repair parts ...............................................................................................	161
Service parts ....................................................................................................................	161
Whole-unit replacement part numbers .............................................................................	161
How to use the parts lists and diagrams ..........................................................................................	162
Assembly locations ...........................................................................................................................	163
Base product (no optional trays or accessories) ..............................................................	163
Covers ..............................................................................................................................................	164
Simplex model .................................................................................................................	164
Duplex model ...................................................................................................................	166
Internal assemblies ..........................................................................................................................	168
Internal assemblies (1 of 3) .............................................................................................	168
Internal assemblies (2 of 3) .............................................................................................	170
Internal assemblies (3 of 3) .............................................................................................	172
PCAs ................................................................................................................................................	174
Alphabetical parts list .......................................................................................................................	176
Numerical parts list ...........................................................................................................................	179
Appendix A Service and support .................................................................................................................	183
Hewlett-Packard limited warranty statement ....................................................................................	184
HP's Premium Protection Warranty: LaserJet print cartridge limited warranty statement ................	185
End User License Agreement ..........................................................................................................	186
Customer self-repair warranty service ..............................................................................................	188
Customer support .............................................................................................................................	188
Repack the product ..........................................................................................................................	189
Service information form ..................................................................................................................	190
Appendix B Specifications ............................................................................................................................	191
Physical specifications .....................................................................................................................	192

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Power consumption ..........................................................................................................................	192
Acoustic specifications .....................................................................................................................	192
Environmental specifications ............................................................................................................	193
Appendix C Regulatory information ............................................................................................................	195
FCC regulations ...............................................................................................................................	196
Declaration of conformity ..................................................................................................................	197
Certificate of Volatility .......................................................................................................................	198
Safety statements .............................................................................................................................	200
Laser safety .....................................................................................................................	200
Canadian DOC regulations ..............................................................................................	200
VCCI statement (Japan) ..................................................................................................	200
Power cord instructions ...................................................................................................	200
Power cord statement (Japan) .........................................................................................	200
EMC statement (Korea) ...................................................................................................	200
Laser statement for Finland .............................................................................................	201
GS statement (Germany) .................................................................................................	201
Substances Table (China) ...............................................................................................	202
Restriction on Hazardous Substances statement (Turkey) .............................................	202
Index .................................................................................................................................................................	203

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List of tables

Table 1-1 Sequence of operation .......................................................................................................................		3
Table 1-2	Motors ................................................................................................................................................	8
Table 1-3	Fans ...................................................................................................................................................	9
Table 1-4 Solenoids and clutches ....................................................................................................................		10
Table 1-5	Switches ...........................................................................................................................................	11
Table 1-6	Sensors ............................................................................................................................................	11
Table 1-7 DC controller controlled components ...............................................................................................		13
Table 1-8 Photo sensors, motor, and solenoid ................................................................................................		32
Table 3-1 Basic problem solving ....................................................................................................................		114
Table 3-2	Status-light legend .........................................................................................................................	128
Table 3-3	Control-panel lights ........................................................................................................................	129
Table 4-1 Order parts, accessories, and supplies ..........................................................................................		160
Table 4-2 Related documentation and software ............................................................................................		160
Table 4-3 Supplies part numbers ...................................................................................................................		160
Table 4-4 Customer replaceable units (CRU) kit part numbers .....................................................................		161
Table 4-5 Whole-unit replacement part numbers ...........................................................................................		161
Table 4-6	Base product ..................................................................................................................................	163
Table 4-7	Simplex model ................................................................................................................................	165
Table 4-8	Duplex model .................................................................................................................................	167
Table 4-9 Internal assemblies (1 of 3) ............................................................................................................		169
Table 4-10 Internal assemblies (2 of 3) ..........................................................................................................		171
Table 4-11 Internal assemblies (3 of 3) ..........................................................................................................		173
Table 4-12	PCAs ............................................................................................................................................	175
Table 4-13 Alphabetical parts list ...................................................................................................................		176
Table 4-14 Numerical parts list .......................................................................................................................		179
Table B-1	Physical specifications1 ..................................................................................................................	192
Table B-2 HP LaserJet Professional P1560 and P1600 Printer series (average in watts)123 .........................		192
Table B-3 HP LaserJet Professional P1560 and P1600 Printer series12 ........................................................		192
Table B-4	Environmental specifications .........................................................................................................	193

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List of figures

Figure 1-1 Product block diagram ......................................................................................................................		2
Figure 1-2	Engine-control system ......................................................................................................................	7
Figure 1-3	Motors ...............................................................................................................................................	8
Figure 1-4	Fans ..................................................................................................................................................	9
Figure 1-5 Solenoids and clutches ...................................................................................................................		10
Figure 1-6	Switches ..........................................................................................................................................	11
Figure 1-7	Sensors ...........................................................................................................................................	11
Figure 1-8 DC controller block diagram ............................................................................................................		13
Figure 1-9 Fuser control circuit .........................................................................................................................		15
Figure 1-10 Fuser-heater control circuit ...........................................................................................................		17
Figure 1-11 Low-voltage power supply (LVPS) ................................................................................................		19
Figure 1-12 High-voltage power supply ............................................................................................................		21
Figure 1-13	Laser/scanner system ...................................................................................................................	22
Figure 1-14 Electrophotographic process block diagram (1 of 2) ....................................................................		24
Figure 1-15 Electrophotographic process block diagram (2 of 2) ....................................................................		25
Figure 1-16 Image formation process ..............................................................................................................		26
Figure 1-17	Primary charging ...........................................................................................................................	27
Figure 1-18 Laser beam exposure ...................................................................................................................		27
Figure 1-19	Print cartridge ................................................................................................................................	28
Figure 1-20	Transfer .........................................................................................................................................	29
Figure 1-21	Separation .....................................................................................................................................	29
Figure 1-22	Fusing ...........................................................................................................................................	30
Figure 1-23	Drum cleaning ...............................................................................................................................	30
Figure 1-24 Pickup, feed, and delivery system block diagram .........................................................................		31
Figure 1-25 Photo sensors, motor, and solenoid .............................................................................................		32
Figure 2-1 Phillips and pozidrive screwdriver comparison ...............................................................................		37
Figure 2-2 Parts removal order ........................................................................................................................		39
Figure 2-3 Remove the pickup roller (1 of 2) ....................................................................................................		40
Figure 2-4 Remove the pickup roller (2 of 2) ....................................................................................................		40
Figure 2-5 Remove the separation pad assembly ...........................................................................................		41
Figure 2-6 Remove the transfer roller ..............................................................................................................		42
Figure 2-7 Remove the tray ..............................................................................................................................		43
Figure 2-8 Remove the output bin tray extension ............................................................................................		44
Figure 2-9 Remove the left cover, simplex product (1 of 4) .............................................................................		45

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Figure 2-10 Remove the left cover, simplex product (2 of 4) ...........................................................................	45
Figure 2-11 Remove the left cover, simplex product (3 of 4) ...........................................................................	46
Figure 2-12 Remove the left cover, simplex product (4 of 4) ...........................................................................	46
Figure 2-13 Remove the left cover, duplex product (1 of 5) .............................................................................	47
Figure 2-14 Remove the left cover, duplex product (2 of 5) .............................................................................	47
Figure 2-15 Remove the left cover, duplex product (3 of 5) .............................................................................	48
Figure 2-16 Remove the left cover, duplex product (4 of 5) .............................................................................	48
Figure 2-17 Remove the left cover, duplex product (5 of 5) .............................................................................	49
Figure 2-18 Remove the right cover, simplex product (1 of 4) .........................................................................	50
Figure 2-19 Remove the right cover, simplex product (2 of 4) .........................................................................	50
Figure 2-20 Remove the right cover, simplex product (4 of 4) .........................................................................	51
Figure 2-21 Remove the right cover, duplex product (1 of 5) ...........................................................................	52
Figure 2-22 Remove the right cover, duplex product (2 of 5) ...........................................................................	52
Figure 2-23 Remove the right cover, duplex product (3 of 5) ...........................................................................	53
Figure 2-24 Remove the right cover, duplex product (4 of 5) ...........................................................................	53
Figure 2-25 Remove the right cover, duplex product (5 of 5) ...........................................................................	54
Figure 2-26 Remove the duplex door, duplex product .....................................................................................	55
Figure 2-27 Remove the duplex frame (1 of 2) ................................................................................................	56
Figure 2-28 Remove the duplex frame (2 of 2) ................................................................................................	56
Figure 2-29 Remove the cartridge door (1 of 3) ...............................................................................................	57
Figure 2-30 Remove the cartridge door (2 of 3) ...............................................................................................	57
Figure 2-31 Remove the cartridge door (3 of 3) ...............................................................................................	58
Figure 2-32 Remove the control panel (1 of 3) ................................................................................................	59
Figure 2-33 Remove the control panel (2 of 3) ................................................................................................	59
Figure 2-34 Remove the control panel (3 of 3) ................................................................................................	60
Figure 2-35 Remove the front cover (1 of 3) ....................................................................................................	61
Figure 2-36 Remove the front cover (2 of 3) ....................................................................................................	62
Figure 2-37 Remove the front cover (3 of 3) ....................................................................................................	62
Figure 2-38 Remove the rear cover, simplex product (1 of 3) ..........................................................................	63
Figure 2-39 Remove the rear cover, simplex product (2 of 3) ..........................................................................	64
Figure 2-40 Remove the rear cover, simplex product (2 of 3) ..........................................................................	64
Figure 2-41 Remove the face-down cover (1 of 2) ...........................................................................................	65
Figure 2-42 Remove the face-down cover (2 of 2) ...........................................................................................	66
Figure 2-43 Remove the formatter PCA (1 of 2) ..............................................................................................	67
Figure 2-44 Remove the formatter PCA (2 of 2) ..............................................................................................	67
Figure 2-45 Remove the laser/scanner assembly (1 of 5) ...............................................................................	68
Figure 2-46 Remove the laser/scanner assembly (2 of 5) ...............................................................................	69
Figure 2-47 Remove the laser/scanner assembly (3 of 5) ...............................................................................	69
Figure 2-48 Remove the laser/scanner assembly (4 of 5) ...............................................................................	70
Figure 2-49 Remove the laser/scanner assembly (5 of 5) ...............................................................................	70
Figure 2-50 Reinstall the laser/scanner assembly ...........................................................................................	71
Figure 2-51 Remove the pickup assembly (1 of 10) ........................................................................................	72
Figure 2-52 Remove the pickup assembly (2 of 10) ........................................................................................	73
Figure 2-53 Remove the pickup assembly (3 of 10) ........................................................................................	73

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Figure 2-54 Remove the pickup assembly (4 of 10) ........................................................................................	74
Figure 2-55 Remove the pickup assembly (5 of 10) ........................................................................................	74
Figure 2-56 Remove the pickup assembly (6 of 10) ........................................................................................	75
Figure 2-57 Remove the pickup assembly (7 of 10) ........................................................................................	75
Figure 2-58 Remove the pickup assembly (8 of 10) ........................................................................................	76
Figure 2-59 Remove the pickup assembly (9 of 10) ........................................................................................	76
Figure 2-60 Remove the pickup assembly (10 of 10) ......................................................................................	77
Figure 2-61 Reinstall the pickup assembly (1 of 4; correct ground spring position) .........................................	78
Figure 2-62 Reinstall the pickup assembly (2 of 4; incorrect ground spring position) ......................................	78
Figure 2-63 Reinstall the pickup assembly (3 of 4; lift plate in raised position) ................................................	79
Figure 2-64 Reinstall the pickup assembly (4 of 4; lift plate in lowered position) .............................................	79
Figure 2-65 Remove the fuser (1 of 10) ...........................................................................................................	80
Figure 2-66 Remove the fuser (2 of 10) ...........................................................................................................	81
Figure 2-67 Remove the fuser (3 of 10) ...........................................................................................................	81
Figure 2-68 Remove the fuser (4 of 10) ...........................................................................................................	82
Figure 2-69 Remove the fuser (5 of 10) ...........................................................................................................	82
Figure 2-70 Remove the fuser (6 of 10) ...........................................................................................................	83
Figure 2-71 Remove the fuser (7 of 10) ...........................................................................................................	83
Figure 2-72 Remove the fuser (8 of 10) ...........................................................................................................	84
Figure 2-73 Remove the fuser (9 of 10) ...........................................................................................................	84
Figure 2-74 Remove the fuser (10 of 10) .........................................................................................................	85
Figure 2-75 Reinstall the fuser; correct wire harness installation .....................................................................	86
Figure 2-76 Reinstall the fuser; incorrect wire harness installation ..................................................................	86
Figure 2-77 Remove the main motor (1 of 9) ...................................................................................................	87
Figure 2-78 Remove the main motor (2 of 9) ...................................................................................................	88
Figure 2-79 Remove the main motor (3 of 9) ...................................................................................................	88
Figure 2-80 Remove the main motor (4 of 9) ...................................................................................................	89
Figure 2-81 Remove the main motor (5 of 9) ...................................................................................................	89
Figure 2-82 Remove the main motor (6 of 9) ...................................................................................................	90
Figure 2-83 Remove the main motor (7 of 9) ...................................................................................................	90
Figure 2-84 Remove the main motor (8 of 9) ...................................................................................................	91
Figure 2-85 Remove the main motor (9 of 9) ...................................................................................................	91
Figure 2-86 Main-motor drive belt: correctly installed ......................................................................................	92
Figure 2-87 Main-motor drive belt: incorrectly installed ....................................................................................	92
Figure 2-88 Remove the pickup solenoid (1 of 7) ............................................................................................	93
Figure 2-89 Remove the pickup solenoid (2 of 7) ............................................................................................	94
Figure 2-90 Remove the pickup solenoid (3 of 7) ............................................................................................	94
Figure 2-91 Remove the pickup solenoid (4 of 7) ............................................................................................	95
Figure 2-92 Remove the solenoid (5 of 7) ........................................................................................................	95
Figure 2-93 Remove the pickup solenoid (6 of 7) ............................................................................................	96
Figure 2-94 Remove the pickup solenoid (7 of 7) ............................................................................................	96
Figure 2-95 Remove the engine controller PCA (1 of 9) ..................................................................................	97
Figure 2-96 Remove the engine controller PCA (2 of 9) ..................................................................................	98
Figure 2-97 Remove the engine controller PCA (3 of 9) ..................................................................................	98

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Figure 2-98 Remove the engine controller PCA (4 of 9) ..................................................................................		99
Figure 2-99 Remove the engine controller PCA (5 of 9) ..................................................................................		99
Figure 2-100 Remove the engine controller PCA (6 of 9) ..............................................................................		100
Figure 2-101 Remove the engine controller PCA (7 of 9) ..............................................................................		100
Figure 2-102 Remove the engine controller PCA (8 of 9) ..............................................................................		101
Figure 2-103 Remove the engine controller PCA (10 of 9) ............................................................................		101
Figure 2-104 Reinstall the engine controller PCA (1 of 4) ..............................................................................		102
Figure 2-105 Reinstall the engine controller PCA (2 of 4) ..............................................................................		102
Figure 2-106 Reinstall the engine controller PCA (3 of 4) ..............................................................................		103
Figure 2-107 Reinstall the engine controller PCA (4 of 4) ..............................................................................		103
Figure 2-108 Remove the duplex-reverse solenoid (1 of 5) ...........................................................................		104
Figure 2-109 Remove the duplex-reverse solenoid (2 of 5) ...........................................................................		105
Figure 2-110 Remove the duplex-reverse solenoid (3 of 5) ...........................................................................		105
Figure 2-111 Remove the duplex-reverse solenoid (4 of 5) ...........................................................................		106
Figure 2-112 Remove the duplex-reverse solenoid (5 of 5) ...........................................................................		106
Figure 2-113 Remove the main fan (1 of 4) ...................................................................................................		107
Figure 2-114 Remove the main fan (2 of 4) ...................................................................................................		108
Figure 2-115 Remove the main fan (3 of 4) ...................................................................................................		108
Figure 2-116 Remove the main fan (4 of 4) ...................................................................................................		109
Figure 2-117 Reinstall the main fan ...............................................................................................................		109
Figure 2-118 Remove the duplex-connector PCA (1 of 5) .............................................................................		110
Figure 2-119 Remove the duplex-connector PCA (2 of 5) .............................................................................		111
Figure 2-120 Remove the duplex-connector PCA (3 of 5) .............................................................................		111
Figure 2-121 Remove the duplex-connector PCA (4 of 5) .............................................................................		112
Figure 2-122 Remove the duplex-connector PCA (5 of 5) .............................................................................		112
Figure 3-1 Sample engine test page ..............................................................................................................		118
Figure 3-2	Plug/jack locations ........................................................................................................................	120
Figure 3-3 Engine controller PCA connectors ................................................................................................		121
Figure 3-4	External view .................................................................................................................................	122
Figure 3-5 Cross section view ........................................................................................................................		123
Figure 3-6 General timing diagram .................................................................................................................		125
Figure 3-7	Circuit diagram ..............................................................................................................................	126
Figure 4-1 Base product (no optional trays or accessories) ...........................................................................		163
Figure 4-2	Simplex model ..............................................................................................................................	164
Figure 4-3	Duplex model ................................................................................................................................	166
Figure 4-4 Internal assemblies (1 of 3) ...........................................................................................................		168
Figure 4-5 Internal assemblies (2 of 3) ...........................................................................................................		170
Figure 4-6 Internal assemblies (3 of 3) ...........................................................................................................		172
Figure 4-7	PCAs .............................................................................................................................................	174

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1 Theory of operation

●Basic operation

●Formatter-control system

●Engine-control system

●Image-formation system

●Pickup, feed, and delivery system

●Main-input tray or priority input slot

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Basic operation

Major product systems

The product contains the following major systems:

●Engine-control system

●Laser/scanner system

●Image-formation system

●Pickup-and-feed system

Product block diagram

Figure 1-1 Product block diagram

LASER/SCANNER SYSTEM

ENGINE CONTROL	IMAGE-FORMATION SYSTEM
SYSTEM

PICKUP-AND-FEED SYSTEM

2 Chapter 1 Theory of operation

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Sequence of operation

The DC controller in the engine-control system controls the operational sequences of the product. The table below describes durations and operations for each period of a print operation from when the product is turned on until the motor stops rotating.

Normal sequence of operation

Table 1-1 Sequence of operation

Name	Timing	Purpose

WAIT	From the time the power switch is turned on, the door	Brings the product to ready state. The product
	is closed or the product exits Sleep mode until the	performs the following during the operations:
	product gets ready for a print operation.	● Detects the print cartridge
		● Detects the print cartridge
		● Heats the fuser film in the fuser
		● Rotates, and the stops, the main motor

STBY (standby) From the end of the WAIT or LSTR period until either a print command is sent or the power switch is turned off.

Maintains the product in printable condition. The product performs the following during the operation:

●Enters Auto-Off mode if Auto-Off command is received

INTR (initial	From the time a print command is received until the
rotation)	paper is picked up.

The product performs the following during the operations:

●Drives the main motor

●Activates the high-voltage power supply

●Activates the laser/scanner

●Warms the fuser heater

PRINT	From the end of the INTR period until the last sheet
	completes the fuser operation.

Forms the image on the photosensitive drum based on the VIDEO signals from the formatter. Transfers and fuses the toner image to the paper.

LSTR (last	From the end of the PRINT period until the main motor
rotation)	stops rotating.

Moves the last printed sheet out of the product. The product performs the following during the operations:

●Stops the main motor

●Deactivates the high-voltage power supply

●Deactivates the laser/scanner

●Deactivates the fuser heater

The product enters the INTR period as the LSTR period is completed, if the formatter sends another print command.

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Formatter-control system

The formatter is responsible for the following procedures:

●Controlling sleep mode

●Receiving and processing print data from the various product interfaces

●Monitoring control-panel functions and relaying product-status information (through the control panel and the network or bidirectional interface)

●Developing and coordinating data placement and timing with the DC controller PCA

●Storing font information

●Communicating with the host computer through the network or the bidirectional interface

The formatter receives a print job from the network or bidirectional interface and separates it into image information and instructions that control the printing process. The DC controller PCA synchronizes the image-formation system with the paper-input and -output systems, and then signals the formatter to send the print-image data.

Sleep mode

NOTE: This product uses an Auto-Off feature for sleep mode.

After a user-specified time, the Auto-Off feature automatically conserves electricity by substantially reducing power consumption when the product is not printing. After a user-specified time, the product automatically reduces its power consumption (Auto-Off). The product returns to the ready state when a button is pressed, a print job is received, or a door is opened. When the product is in Auto-Off mode, all of the control-panel LEDs and the power button backlight LED are off.

NOTE: Although the product lights are off in Auto-Off mode, the product functions normally when it receives a print job.

Input/output

The product receives print data primarily from the following:

●Hi-Speed USB 2.0 port

●802.11b/g wireless networking (wireless models only)

CPU

The formatter incorporates a 400 MHz Helium processor.

Memory

The random access memory (RAM) on the formatter PCA contains the page, I/O buffers, and the font storage area. RAM stores printing and font information received from the host system, and can also serve to temporarily store a full page of print-image data before the data is sent to the print engine.

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Firmware

●HP LaserJet Professional P1560 Printer series

◦The product has 8 MB of Synchronous DRAM, which is used for run-time firmware imaging and specific print job information for the print job.

●HP LaserJet Professional P1600 Printer series

◦The product has 32 MB of Synchronous DRAM, which is used for run-time firmware imaging and specific print job information for the print job.

Memory use

●HP LaserJet Professional P1560 Printer series

◦The product has a 2 KB EEPROM and 64 MB of NAND Flash Memory, which is used for product configuration information and printer driver firmware.

●HP LaserJet Professional P1600 Printer series

◦The product has a 8 KB EEPROM and 64 MB of NAND Flash Memory, which is used for product configuration information and printer driver firmware.

PJL overview

The printer job language (PJL) is an integral part of configuration, in addition to the standard printer command language (PCL). With standard cabling, the product can use PJL to perform a variety of functions such as these:

●Two-way communication with the host computer through a network connection or a USB connection. The product can inform the host about such things as the control-panel settings, and the control-panel settings can be changed from the host.

●Dynamic I/O switching. The product uses this switching to be configured with a host on each I/O. The product can receive data from more than one I/O simultaneously, until the I/O buffer is full. This can occur even when the product is offline.

●Context-sensitive switching. The product can automatically recognize the personality (PS or PCL) of each job and configure itself to serve that personality.

●Isolation of print environment settings from one print job to the next. For example, if a print job is sent to the product in landscape mode, the subsequent print jobs print in landscape mode only if they are formatted for landscape printing.

LEDM overview

NOTE: HP LaserJet Professional P1600 Printer series

The low-end data model (LEDM) provides one consistent data representation method and defines the dynamic and capabilities tickets shared between clients and devices, as well as the access protocol, event, security, and discovery methods.

ACL overview

The advanced control language (ACL) is a language that supports product control and firmware downloads in printers that support both PJL/PCL and host-based printing. Each sequence of ACL

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commands must be preceded by a unified exit command (UEL) and an @PJL ENTER LANGUAGE=ACL command. The ACL sequence is always followed by a UEL. Any number of commands can be placed between the UELs. The only exception to these rules is the download command. If a firmware download is done, the download command must be the last command in the sequence. It will not be followed by a UEL.

The firmware searches for the UEL sequence when parsing commands. However, while downloading binary data such as host-based code or NVRAM data the firmware suspends UEL parsing. To handle hosts that “disappear” during binary sequences, the firmware times out all ACL command sessions. If a timeout occurs during a non-download command sequence, it is treated as the receipt of a UEL. If a timeout occurs during firmware download the product resets.

Control panel

The formatter sends and receives product status and command data to and from the control-panel PCA.

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Engine-control system

The engine-control system coordinates all product functions, according to commands that the formatter sends. The engine-control system drives the laser/scanner system, the image-formation system, and the pickup/feed/delivery system.

The engine control system contains the following major components:

●Engine-control unit (ECU)

◦DC controller

◦Low-voltage power supply

●High-voltage power supply

●Fuser control

Figure 1-2 Engine-control system

ENGINE CONTROL SYSTEM

DC controller

Low-voltage power supply

LASER/SCANNER SYSTEM

Formatter

IMAGE-FORMATION SYSTEM

High-voltage power supply

MEDIA-FEED SYSTEM

Fuser control

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Motors, fans, clutches, solenoids, switches, and sensors

Figure 1-3 Motors

Table 1-2 Motors

Item	Description	Components driven

M1	Main motor	●	Pickup roller
		●	Feed roller
		●	Photosensitive drum
		●	Developing roller
		●	Pressure roller
		●	Delivery roller
		●	Duplex feed roller

M2	Scanner motor	●	Scanner mirror

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Figure 1-4 Fans

FM1

Table 1-3 Fans

Item	Description

FM1	Main fan

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Figure 1-5 Solenoids and clutches

SL2

SL1

Table 1-4 Solenoids and clutches

Item	Description

SL1	Pickup solenoid

SL2	Duplex reverse solenoid
	NOTE: Duplex models only.

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Figure 1-6 Switches

Table 1-5 Switches
Item	Description
SW501	Cartridge-door switch
SW502	Power switch; not shown
Figure 1-7	Sensors
	PS702
	PS701
	PS751
Table 1-6 Sensors
Item	Description
PS701	Fuser delivery sensor

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Table 1-6 Sensors (continued)

Item	Description

PS702	Media-width sensor

PS751	Top-of-Page (TOP) sensor

PS901	Main-motor rotation-number sensor; not shown

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