HP LaserJet Pro Color MFP M476 Repair Manual and Troubleshooting Manual

4.6 (13)

HP Color LaserJet Pro MFP M476

Replace and Repair 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.

Edition 1, 04/2014

Trademark Credits

Microsoft®, Windows®, Windows® XP, Windows Vista®, Windows® 7, Windows® 8, and Windows® 8.1 are U.S. registered trademarks of Microsoft Corporation.

ENERGY STAR and the ENERGY STAR mark are registered U.S. marks.

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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Table of contents

1 Removal and replacement ..............................................................................................................................	1
Removal and replacement strategy ......................................................................................................................	2
Introduction .........................................................................................................................................	2
Considerations during removal and replacement ..............................................................................	2
Electrostatic discharge ........................................................................................................................	2
Required tools .....................................................................................................................................	3
Accessing the 2ndary service menu ....................................................................................................	4
Fasteners used in this product ............................................................................................................	5
Service approach ...................................................................................................................................................	6
Before performing service ..................................................................................................................	6
After performing service .....................................................................................................................	6
Post-service tests ...............................................................................................................................	7
Print-quality test ..............................................................................................................	7
Copy quality test ...............................................................................................................	7
Fax quality test (fax models only) ....................................................................................	7
Removal and replacement procedures .................................................................................................................	8
Rollers and pads ..................................................................................................................................	8
Transfer roller ...................................................................................................................	8
Pickup roller (Tray 2 or Tray 3) .........................................................................................	9
Separation roller (Trays 2 or 3) ......................................................................................	11
Reinstall the separation roller .....................................................................	12
Document feeder pickup roller assembly ......................................................................	13
Pickup roller and separation pad (Tray 1) ......................................................................	14
Scanner and document feeder ..........................................................................................................	17
Scanner assembly ...........................................................................................................	17
Document feeder ............................................................................................................	18
Remove the scanner cable cover .................................................................	18
Remove the document feeder .....................................................................	21
Reinstall the document feeder ....................................................................	22
Covers and doors ...............................................................................................................................	22
Print-cartridge drawer ....................................................................................................	22
Right cover ......................................................................................................................	25

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Right-front cover and power button ..............................................................................	26
Rear-upper cover ............................................................................................................	28
Paper-feed guide assembly ............................................................................................	29
Rear door .........................................................................................................................	30
Rear-lower cover and rear-door links ............................................................................	32
Remove the rear-lower cover and rear-door links ......................................	32
Rear-door rib assembly ..................................................................................................	36
Remove the rear-door rib assembly ............................................................	36
Control panel and right-arm mount ...............................................................................	39
Reinstall the control panel and right-arm mount .......................................	40
Upper-cover assembly ....................................................................................................	42
Remove the upper-cover assembly .............................................................	42
Reinstall the upper-cover assembly ............................................................	43
Left cover ........................................................................................................................	45
Remove the left cover ..................................................................................	45
Reinstall the left cover .................................................................................	47
Front-door assembly ......................................................................................................	48
Remove the front-door assembly ................................................................	48
Internal assemblies ...........................................................................................................................	54
Intermediate transfer belt (ITB) .....................................................................................	54
Reinstall the ITB ...........................................................................................	57
Drum motor (M1) and developer motor (M2) .................................................................	58
Reinstall the drum motor (M1) and developer motor (M2) .........................	63
Intermediate PCA ............................................................................................................	64
Formatter PCA .................................................................................................................	65
Remove the formatter PCA ..........................................................................	65
Fax PCA ............................................................................................................................	66
Wireless PCA ...................................................................................................................	68
DC controller PCA ............................................................................................................	69
Remove the DC controller PCA .....................................................................	69
Fuser-motor assembly ...................................................................................................	71
Remove the fuser-motor assembly .............................................................	71
Reinstall the fuser-motor assembly ............................................................	74
High-voltage power-supply PCA ....................................................................................	75
Remove the high-voltage power-supply PCA ..............................................	75
Color-misregistration sensor assembly .........................................................................	78
Remove the color-misregistration sensor assembly ..................................	78
Reinstall the color-misregistration sensor assembly .................................	80
Fan (FM1) .........................................................................................................................	82
USB PCA (fax/memory-card models) .............................................................................	83
Remove the USB PCA ....................................................................................	83

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Duplex-reverse drive assembly .....................................................................................	84
Remove the duplex-reverse drive assembly ...............................................	84
Fuser ...............................................................................................................................	87
Remove the fuser .........................................................................................	87
Reinstall the fuser ........................................................................................	92
Paper-delivery assembly ................................................................................................	93
Remove the paper-delivery assembly .........................................................	93
Low voltage power supply ..............................................................................................	95
Trays ................................................................................................................................................	104
Tray cassettes and optional Tray 3 assembly .............................................................	105
2 Parts and diagrams ....................................................................................................................................	107
Order parts, accessories, and supplies .............................................................................................................	108
Orderable parts .................................................................................................................................................	109
Accessories ......................................................................................................................................	109
Toner cartridges ..............................................................................................................................	109
Customer self repair (CSR) and service kits ....................................................................................	109
Whole unit replacement (WUR) .........................................................................................................................	110
Service parts ......................................................................................................................................................	111
Related documentation and software ..............................................................................................................	111
How to use the parts lists and diagrams ..........................................................................................................	112
Scanner and document feeder main assembly ................................................................................................	114
Covers ................................................................................................................................................................	116
Internal assemblies ...........................................................................................................................................	118
Internal assemblies (1 of 7) ............................................................................................................	118
Internal assemblies (2 of 7) ............................................................................................................	120
Internal assemblies (3 of 7) ............................................................................................................	122
Internal assemblies (4 of 7) ............................................................................................................	124
Internal assemblies (5 of 7) ............................................................................................................	126
Internal assemblies (6 of 7) ............................................................................................................	128
Internal assemblies (7 of 7) ............................................................................................................	130
PCAs .................................................................................................................................................	132
Accessories ........................................................................................................................................................	134
250-sheet paper feeder accessory kit (optional Tray 3) ...............................................................	134
Alphabetical parts list .......................................................................................................................................	136
Numerical parts list ...........................................................................................................................................	139
Index ...........................................................................................................................................................	143

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List of tables

Table 1-1 Common fasteners ..............................................................................................................................................		5
Table 2-1	Accessories .......................................................................................................................................................	109
Table 2-2	Toner cartridges ...............................................................................................................................................	109
Table 2-3 Customer self repair (CSR) and service kits .....................................................................................................		109
Table 2-4 Pro 400 Color MFP M476 nw ............................................................................................................................		110
Table 2-5 Pro 400 Color MFP M476 dn .............................................................................................................................		110
Table 2-6 Pro 400 Color MFP M476 dw ............................................................................................................................		110
Table 2-7	Service parts ....................................................................................................................................................	111
Table 2-8 Related documentation and software .............................................................................................................		111
Table 2-9 Scanner and document feeder main assembly ...............................................................................................		115
Table 2-10	Covers .............................................................................................................................................................	117
Table 2-11 Internal assemblies (1 of 7) ...........................................................................................................................		119
Table 2-12 Internal assemblies (2 of 7) ...........................................................................................................................		121
Table 2-13 Internal assemblies (3 of 7) ...........................................................................................................................		123
Table 2-14 Internal assemblies (4 of 7) ...........................................................................................................................		125
Table 2-15 Internal assemblies (5 of 7) ...........................................................................................................................		127
Table 2-16 Internal assemblies (6 of 7) ...........................................................................................................................		129
Table 2-17 Internal assemblies (7 of 7) ...........................................................................................................................		131
Table 2-18	PCAs ................................................................................................................................................................	133
Table 2-19 250-sheet paper feeder accessory kit (optional Tray 3) ..............................................................................		135
Table 2-20 Alphabetical parts list ....................................................................................................................................		136
Table 2-21 Numerical parts list ........................................................................................................................................		139

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List of figures

Figure 1-1 Phillips and pozidrive screwdriver comparison ..................................................................................................	3
Figure 1-2 Raise the front of the product ..........................................................................................................................	10
Figure 1-3 Remove the pickup roller ..................................................................................................................................	10
Figure 1-4 Remove the pickup roller (1 of 3) .....................................................................................................................	11
Figure 1-5 Remove the separation roller (2 of 3) ..............................................................................................................	11
Figure 1-6 Remove the separation roller (3 of 3) ..............................................................................................................	12
Figure 1-7 Reinstall the separation roller ..........................................................................................................................	12
Figure 1-8 Open the jam-access cover ...............................................................................................................................	13
Figure 1-9 Remove the document feeder pickup roller assembly ....................................................................................	13
Figure 1-10 Remove the Tray 1 pickup roller (1 of 3) ........................................................................................................	14
Figure 1-11 Raise the front of the product ........................................................................................................................	15
Figure 1-12 Remove the Tray 1 pickup roller (3 of 3) ........................................................................................................	15
Figure 1-13 Remove the Tray 1 separation pad ................................................................................................................	16
Figure 1-14 Disconnect the ground cable, connector, and FFCs .......................................................................................	17
Figure 1-15 Remove four screws .......................................................................................................................................	17
Figure 1-16 Lift and slide the scanner assembly ...............................................................................................................	18
Figure 1-17 Lift the scanner up and off the product .........................................................................................................	18
Figure 1-18 Turn the scanner assembly over ....................................................................................................................	19
Figure 1-19 Remove three screws, then remove the cable cover .....................................................................................	20
Figure 1-20 Remove three screws, then remove the cable cover .....................................................................................	20
Figure 1-21 Release the cables ..........................................................................................................................................	21
Figure 1-22 Remove the document feeder assembly .......................................................................................................	21
Figure 1-23 Remove the print-cartridge drawer (1 of 3) ...................................................................................................	23
Figure 1-24 Remove the print-cartridge drawer (2 of 3) ...................................................................................................	23
Figure 1-25 Remove the print-cartridge drawer (3 of 3) ...................................................................................................	24
Figure 1-26 Remove the right cover (1 of 2) ......................................................................................................................	25
Figure 1-27 Remove the right cover (2 of 2) ......................................................................................................................	25
Figure 1-28 Remove the rear-upper cover (1 of 2) ............................................................................................................	28
Figure 1-29 Remove the rear-upper cover (2 of 2) ............................................................................................................	28
Figure 1-30 Remove the feed assembly (1 of 2) ................................................................................................................	29
Figure 1-31 Remove the feed assembly (2 of 2) ................................................................................................................	29
Figure 1-32 Close the duplex-feed assembly ....................................................................................................................	30

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Figure 1-33 Remove two screws ........................................................................................................................................	30
Figure 1-34 Remove the rear door .....................................................................................................................................	31
Figure 1-35 Remove the rearlower cover and rear-door links (1 of 6) ...........................................................................	32
Figure 1-36 Remove the rear-lower cover and rear-door links (2 of 6) ............................................................................	33
Figure 1-37 Remove the rear-lower cover and rear-door links (3 of 6) ............................................................................	33
Figure 1-38 Remove the rear-lower cover and link-guides (4 of 6) ..................................................................................	34
Figure 1-39 Remove the rear-lower cover and link-guides (5 of 6) ..................................................................................	34
Figure 1-40 Remove the rear-lower cover and rear-door links (6 of 6) ............................................................................	35
Figure 1-41 Remove the rear-door rib assembly (1 of 3) ..................................................................................................	36
Figure 1-42 Remove the rear-door rib assembly (2 of 3) ..................................................................................................	37
Figure 1-43 Remove the rear-door rib assembly (2 of 3) ..................................................................................................	37
Figure 1-44 Remove the rear-door rib assembly (3 of 3) ..................................................................................................	38
Figure 1-45 Disconnect FFCs and connectors and loosen ferrite ......................................................................................	39
Figure 1-46 Remove four screws and disconnect the ground wire ...................................................................................	39
Figure 1-47 Remove the right-arm mount ........................................................................................................................	40
Figure 1-48 Install four screws and connect the ground wire ...........................................................................................	40
Figure 1-49 Connect FFCs and connectors and replace ferrite .........................................................................................	41
Figure 1-50 Remove four screws .......................................................................................................................................	42
Figure 1-51 Raise the back of the cover up and off the product .......................................................................................	42
Figure 1-52 Remove the upper-cover assembly ...............................................................................................................	43
Figure 1-53 Reinstall the upper-cover assembly (1 of 3) ..................................................................................................	43
Figure 1-54 Reinstall the upper-cover assembly (2 of 3) ..................................................................................................	44
Figure 1-55 Reinstall the upper-cover assembly (3 of 3) ..................................................................................................	44
Figure 1-56 Remove the left cover (1 of 3) ........................................................................................................................	45
Figure 1-57 Remove the left cover (2 of 3) ........................................................................................................................	46
Figure 1-58 Remove the left cover (3 of 3) ........................................................................................................................	46
Figure 1-59 Reinstall the left cover (1 of 2) .......................................................................................................................	47
Figure 1-60 Reinstall the left cover (2 of 2) .......................................................................................................................	47
Figure 1-61 Remove the front-door assembly (1 of 10) ...................................................................................................	48
Figure 1-62 Remove the front-door assembly (2 of 10) ...................................................................................................	49
Figure 1-63 Remove the front-door assembly (3 of 10) ...................................................................................................	49
Figure 1-64 Remove the front-door assembly (4 of 10) ...................................................................................................	50
Figure 1-65 Remove the front-door assembly (5 of 10) ...................................................................................................	50
Figure 1-66 Remove the front-door assembly (6 of 10) ...................................................................................................	51
Figure 1-67 Remove the front-door assembly (7 of 10) ...................................................................................................	51
Figure 1-68 Remove the front-door assembly (8 of 10) ...................................................................................................	52
Figure 1-69 Remove the front-door assembly (9 of 10) ...................................................................................................	52
Figure 1-70 Remove the front-door assembly (10 of 10) .................................................................................................	53
Figure 1-71 Remove the ITB (1 of 6) ..................................................................................................................................	54
Figure 1-72 Remove the ITB (2 of 6) ..................................................................................................................................	54
Figure 1-73 Remove the ITB (3 of 6) ..................................................................................................................................	55

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Figure 1-74 Remove the ITB (4 of 6) ..................................................................................................................................	55
Figure 1-75 Remove the ITB (5 of 6) ..................................................................................................................................	56
Figure 1-76 Remove the ITB (6 of 6) ..................................................................................................................................	56
Figure 1-77 Diagnostic page ..............................................................................................................................................	57
Figure 1-78 Remove motor M1 and motor M2 (1 of 6) ......................................................................................................	58
Figure 1-79 Remove motor M1 and motor M2 (2 of 6) ......................................................................................................	59
Figure 1-80 Remove motor M1 and motor M2 (3 of 6) ......................................................................................................	60
Figure 1-81 Remove motor M1 and motor M2 (4 of 6) ......................................................................................................	61
Figure 1-82 Remove motor M1 and motor M2 (5 of 6) ......................................................................................................	61
Figure 1-83 Remove motor M1 and motor M2 (6 of 6) ......................................................................................................	62
Figure 1-84 Reinstall the motor M1 and motor M2 wire-harness retainer .......................................................................	63
Figure 1-85 Remove the Intermediate PCA (1 of 2) ...........................................................................................................	64
Figure 1-86 Remove the Intermediate PCA (2 of 2) ...........................................................................................................	64
Figure 1-87 Remove the formatter PCA (1 of 2) ................................................................................................................	66
Figure 1-88 Remove the formatter PCA (2 of 2) ................................................................................................................	66
Figure 1-89 Remove the fax PCA ........................................................................................................................................	67
Figure 1-90 Remove the wireless PCA ...............................................................................................................................	68
Figure 1-91 Remove the DC controller PCA (1 of 2) ...........................................................................................................	70
Figure 1-92 Remove the DC controller PCA (2 of 2) ...........................................................................................................	70
Figure 1-93 Remove the fuser-motor assembly (1 of 6) ...................................................................................................	71
Figure 1-94 Remove the fuser-motor assembly (2 of 6) ...................................................................................................	72
Figure 1-95 Remove the fuser-motor assembly (3 of 6) ...................................................................................................	72
Figure 1-96 Remove the fuser-motor assembly (4 of 6) ...................................................................................................	73
Figure 1-97 Remove the fuser-motor assembly (5 of 6) ...................................................................................................	73
Figure 1-98 Remove the fuser-motor assembly (6 of 6) ...................................................................................................	74
Figure 1-99 Reinstall the fuser-motor assembly ..............................................................................................................	74
Figure 1-100 Remove the high-voltage power-supply PCA (1 of 5) .................................................................................	75
Figure 1-101 Remove the high-voltage power-supply PCA (2 of 5) .................................................................................	76
Figure 1-102 Remove the high-voltage power-supply PCA (3 of 5) .................................................................................	76
Figure 1-103 Remove the high-voltage power-supply PCA (4 of 5) .................................................................................	77
Figure 1-104 Remove the high-voltage power-supply PCA (5 of 5) .................................................................................	77
Figure 1-105 Remove the color-misregistration sensor assembly PCA (1 of 4) ..............................................................	78
Figure 1-106 Remove the color-misregistration sensor assembly PCA (2 of 4) ..............................................................	79
Figure 1-107 Remove the color-misregistration sensor assembly PCA (3 of 4) ..............................................................	79
Figure 1-108 Remove the color-misregistration sensor assembly PCA (4 of 4) ..............................................................	80
Figure 1-109 Reinstall the color-misregistration sensor assembly PCA (1 of 2) .............................................................	80
Figure 1-110 Reinstall the color-misregistration sensor assembly PCA (2 of 2) .............................................................	81
Figure 1-111 Remove the fan (FM1) (1 of 2) ......................................................................................................................	82
Figure 1-112 Remove the fan (FM1) (2 of 2) ......................................................................................................................	82
Figure 1-113 Remove the USB PCA (fax/memory-card models) .......................................................................................	83
Figure 1-114 Remove the duplex-reverse drive assembly (1 of 4) ...................................................................................	84

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Figure 1-115 Remove the duplex-reverse drive assembly (2 of 4) ...................................................................................	85
Figure 1-116 Remove the duplex-reverse drive assembly (3 of 4) ...................................................................................	85
Figure 1-117 Remove the duplex-reverse drive assembly (4 of 4) ...................................................................................	86
Figure 1-118 Remove the fuser (1 of 8) .............................................................................................................................	87
Figure 1-119 Remove the fuser (2 of 8) .............................................................................................................................	88
Figure 1-120 Remove the fuser (3 of 8) .............................................................................................................................	88
Figure 1-121 Remove the fuser (4 of 8) .............................................................................................................................	89
Figure 1-122 Remove the fuser (5 of 8) .............................................................................................................................	89
Figure 1-123 Remove the fuser (6 of 8) .............................................................................................................................	90
Figure 1-124 Remove the fuser (7 of 8) .............................................................................................................................	90
Figure 1-125 Remove the fuser (8 of 8) .............................................................................................................................	91
Figure 1-126 Reinstall the fuser ........................................................................................................................................	92
Figure 1-127 Remove the paper-delivery assembly (1 of 4) ............................................................................................	93
Figure 1-128 Remove the paper-delivery assembly (2 of 4) ............................................................................................	94
Figure 1-129 Remove the paper-delivery assembly (3 of 4) ............................................................................................	94
Figure 1-130 Remove the paper-delivery assembly (4 of 4) ............................................................................................	95
Figure 1-131 Remove three screws ...................................................................................................................................	96
Figure 1-132 Original routing of wires to be removed ......................................................................................................	97
Figure 1-133 DCC plugs disconnected ................................................................................................................................	97
Figure 1-134 Unplugged wires have been removed from the wire guides and plugs from the Driver PCA have
been disconnected .................................................................................................................................................................	98
Figure 1-135 Disconnect the plug on the formatter board ...............................................................................................	98
Figure 1-136 Plastic wire frame .........................................................................................................................................	99
Figure 1-137 Tabs to release .............................................................................................................................................	99
Figure 1-138 Remove one screw .....................................................................................................................................	100
Figure 1-139 Remove one screw above and left of the power switch ............................................................................	100
Figure 1-140 Remove the screw holding the tray 3 harness in place .............................................................................	101
Figure 1-141 Remove the tray 3 harness and pin guide .................................................................................................	101
Figure 1-142 Remove the screws securing the low voltage power supply ....................................................................	102
Figure 1-143 Remove the screw securing the top of the low voltage power supply .....................................................	102
Figure 1-144 Lift the low voltage power supply .............................................................................................................	103
Figure 1-145 Disconnect two plugs .................................................................................................................................	103
Figure 1-146 Remove the ground strap ...........................................................................................................................	104
Figure 1-147 Remove the low voltage power supply ......................................................................................................	104
Figure 1-148 Remove the tray cassettes and optional Tray 3 assembly (1 of 2) ...........................................................	105
Figure 1-149 Remove the tray cassettes and optional Tray 3 assembly (2 of 2) ...........................................................	105
Figure 2-1 Scanner and document feeder main assembly ..............................................................................................	114
Figure 2-2 External panels and covers ............................................................................................................................	116
Figure 2-3 Internal assemblies (1 of 7) ............................................................................................................................	118
Figure 2-4 Internal assemblies (2 of 7) ............................................................................................................................	120
Figure 2-5 Internal assemblies (3 of 7) ............................................................................................................................	122

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Figure 2-6	Internal assemblies (4 of 7) ............................................................................................................................	124
Figure 2-7	Internal assemblies (5 of 7) ............................................................................................................................	126
Figure 2-8	Internal assemblies (6 of 7) ............................................................................................................................	128
Figure 2-9	Internal assemblies (7 of 7) ............................................................................................................................	130
Figure 2-10	PCAs ..............................................................................................................................................................	132
Figure 2-11	250-sheet paper feeder (optional Tray 3) ...................................................................................................	134

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1Removal and replacement

●Removal and replacement strategy

●Service approach

●Removal and replacement procedures

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Removal and replacement strategy

Use this section to find procedures for the removal and replacement of field replaceable units (FRUs).

Introduction

This chapter describes the removal and replacement of field-replaceable units (FRUs) only.

Replacing FRUs is generally the reverse of removal. Occasionally, notes and tips are included to provide directions for difficult or critical replacement procedures.

HP does not support repairing individual subassemblies or troubleshooting to the component level.

Note the length, diameter, color, type, and location of each screw. Be sure to return each screw to its original location during reassembly.

Incorrectly routed or loose wire harnesses can interfere with other internal components and can become damaged or broken. Frayed or pinched harness wires can be difficult to find. When replacing wire harnesses, always use the provided wire loops, lance points, or wire-harness guides and retainers.

Considerations during removal and replacement

WARNING! Turn the product off, wait 5 seconds, and then remove the power cord before attempting to service the product. If this warning is not followed, severe injury can result, in addition to damage to the product. The power must be on for certain functional checks during troubleshooting. However, disconnect the power supply during parts removal.

Never operate or service the product with the protective cover removed from the laser/scanner assembly. The reflected beam, although invisible, can damage your eyes.

The sheet-metal parts might have sharp edges. Be careful when handling sheet-metal parts.

CAUTION: Do not bend or fold the flat flexible cables (FFCs) during removal or installation. Also, do not straighten pre-folds in the FFCs. You must fully seat all FFCs in their connectors. Failure to fully seat an FFC into a connector can cause a short circuit in a PCA.

NOTE: To install a self-tapping screw, first turn it counterclockwise to align it with the existing thread pattern, and then carefully turn it clockwise to tighten. Do not overtighten. If a self-tapping screw-hole becomes stripped, repair the screw-hole or replace the affected assembly.

TIP: For clarity, some photos in this chapter show components removed that would not be removed to service the product. If necessary, remove the components listed at the beginning of a procedure before proceeding to service the product.

Electrostatic discharge

		CAUTION:		Some parts are sensitive to electrostatic discharge (ESD). Look for the ESD reminder when

removing product parts. Always perform service work at an ESD-protected workstation or mat, or use an ESD strap. If an ESD workstation, mat, or strap is not available, ground yourself by touching the sheet-metal chassis before touching an ESD-sensitive part.

Protect the ESD-sensitive parts by placing them in ESD pouches when they are out of the product.

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Required tools

●Number 2 Phillips screwdriver with a magnetic tip and a 152-mm (6-inch) shaft length

●Precision slotted (flat head) screwdriver with a 1 mm (0.04 in) blade width

NOTE: This fine-point tool is required to release the front door pins. The width of the blade must be 2 mm (0.08 in) or less to be able to drive the door pins out of the mounting holes.

●Small, slotted (flat head) screwdriver

●Needle-nose pliers

●Snap-ring pliers

●ESD mat (if one is available)

●Penlight (optional)

CAUTION: Always use a Phillips screwdriver (callout 1). Do not use a pozidrive screwdriver (callout 2) or any motorized screwdriver. These can damage screws or screw threads.

Figure 1-1 Phillips and pozidrive screwdriver comparison

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Accessing the 2ndary service menu

NOTE: If the 2ndary Service menu bar does not appear, repeat steps 2 and 3.

1.On the Home screen of the touch display, touch Setup Menu to open the Setup menu.

2.On the Setup Menu screen of the touch display, simultaneously touch the hidden Left Arrow and Cancel icons.

NOTE: The Left Arrow and Cancel icons might not be illuminated. Use the following image to make sure that you touch the correct areas of the touchscreen.

3.After pressing both symbols, the Home screen should reappear. Touch the Setup Menu icon to access the 2ndary Service Menu bar.

4.From the Service Menu, touch the 2ndary Service Menu bar.

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Fasteners used in this product

WARNING! Make sure that components are replaced with the correct screw type. Using the incorrect screw (for example, substituting a long screw for the correct shorter screw) can cause damage to the product or interfere with product operation. Do not intermix screws that are removed from one component by using the screws that are removed from another component.

NOTE: The screw illustrations in the following table are for reference only. Screws might vary in size and appearance from those shown in this table.

Table 1-1 Common fasteners

Example	Description	Size	Part Number
	Screw, with washer	M3X8	XA9-1420-000CN
		M4X6	XB2-7400-605CN
		M4X12	XA9-1422-000CN
	Screw, tapping, truss head	M4X10	XB4-7401-005CN
		M4X15	XB4-7401-609CN
	Screw, TP	M3X4	XB6-7300-405CN
		M3X6	XB6-7300-605CN
	Screw, D	M3X6	XA9-1670-000CN
		M3X8	XA9-1671-000CN
	Screw, machine	M3X4	XB6-7300-409CN
	Screw, machine, flat head	M3X4	XA9-0679-000CN
	Screw, machine, flanged pan	M3X6	XB6-7300-805CN
	head

12 mm

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Service approach

Before performing service

●Remove all media from the product.

●Turn off the power using the power switch.

●Unplug the power cable and interface cable(s).

●Place the product on an ESD mat (if one is available). If an ESD workstation or mat is not available, ground yourself by touching the sheet-metal chassis before touching an ESD-sensitive part.

●Remove the toner cartridges.

●Remove the tray 2 cassette.

After performing service

●Connect the power cable.

●Reinstall the toner cartridges.

●Reinstall the tray 2 cassette.

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Post-service tests

After service has been completed, perform the following tests to verify that the repair or replacement was successful.

Print-quality test

1.Verify that you have completed the necessary reassembly steps.

2.Make sure that the input tray contains clean, unmarked paper.

3.Attach the power cable and interface cable, and then turn on the product.

4.Verify that the expected start-up sounds occur.

5.Print a configuration page, and then verify that the expected printing sounds occur.

6.Print a demo page, and then verify that the print quality is as expected.

7.Send a print job from the host computer, and then verify that the output meets expectations.

8.If necessary, restore any customer-specified settings.

9.Clean the outside of the product by using a damp cloth.

Copy quality test

1.Verify that you have completed the necessary reassembly steps.

2.Perform steps 1-8 in test 1 to check basic print quality.

3.Place the configuration page in the document feeder.

4.Print a copy job, and then verify the results.

5.Clean the outside of the product by using a damp cloth.

Fax quality test (fax models only)

1.Place the configuration page in the document feeder.

2.Type a valid fax number and send the fax job.

3.Verify that the send quality and receive quality meet expectations.

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Removal and replacement procedures

Rollers and pads

Transfer roller

The transfer roller is a component of the paper-feed assembly and not available as an individual FRU. To remove and replace the transfer roller, install a replacement paper-feed guide assembly. See Paper-feed guide assembly on page 29.

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Pickup roller (Tray 2 or Tray 3)

The roller must be rotated into the service position to remove it.

CAUTION: Avoid touching the spongy roller surface unless you are going to replace the roller. Skin oils on the roller can cause paper pickup problems.

1.Turn the product on, and wait for it to reach the Ready state. Perform the following steps to rotate the roller to the service position.

NOTE: If you have removed Tray 2 to service the product, reinstall the tray before turning the power on.

TIP: The following steps rotate the engine pickup roller and the Tray 1 pickup roller into the service position.

a.Open the 2ndary service menu. See Accessing the 2ndary service menu on page 4

b.Scroll down, then touch the Pick Roller item.

Touch the OK button to confirm that you want the roller to rotate.

c.Listen for the roller to rotate. When the roller is done rotating, unplug the power cable and then place the power button in the off position.

CAUTION: It is important to place the power button in the off position after unplugging the power cable so that the product power does not come on immediately when the power cable is plugged in again.

d.Remove Tray 2.

e.Perform the remaining steps in this procedure to remove the roller. After replacing the roller, plug the power cable into the product, and then use the power button to turn the power on.

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2.Carefully raise the front of the product.

WARNING! Do not place the product face-up resting on the rear cover and rear door unless you have removed all toner cartridges. Excess toner might enter the laser/scanner assembly and contaminate the mirrors, causing print-quality problems. The laser/scanner is not a FRU. If the laser/scanner mirrors are contaminated, the entire product must be replaced.

CAUTION: The document feeder and scanner cover are not captive and can open suddenly when the product is placed front-side face up. Always support the document feeder and scanner cover before placing the product front-side face up.

Do not lift the product grasping the front door and Tray 2 cavity.

NOTE: The roller is located inside the tray cavity.

Figure 1-2 Raise the front of the product

3.Use a precision slotted (flat head) screwdriver to release two locking tabs and remove the pickup roller.

CAUTION: Do not touch the spongy roller surface unless you are going to replace the roller. Skin oils on the roller can cause paper pickup problems.

Figure 1-3 Remove the pickup roller

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Separation roller (Trays 2 or 3)

CAUTION: Avoid touching the spongy roller surface unless you are going to replace the roller. Skin oils on the roller can cause paper pickup problems.

1.Remove Tray 2 (if installed), and then carefully raise the front of the product.

WARNING! Do not place the product face-up resting on the rear cover and rear door. Excess toner might enter the laser/scanner assembly and contaminate the mirrors, causing print-quality problems. The laser/scanner is not a FRU. If the laser/scanner mirrors are contaminated, the entire product must be replaced.

CAUTION: Do not lift the product grasping the front door and Tray 2 cavity.

NOTE: The roller is located inside the tray cavity.

Figure 1-4 Remove the pickup roller (1 of 3)

2.Shift the cover to one side and pull it over the shaft, then slide the cover the other way to slide it off the shaft and remove it.

Figure 1-5 Remove the separation roller (2 of 3)

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3.Wedge a small precision slotted (flat head) screwdriver under the left side of the roller holder to release and remove the separation roller.

Figure 1-6 Remove the separation roller (3 of 3)

Reinstall the separation roller

1.Install the replacement separation roller.

2.Reinstall the separation roller cover on the locking pins, and then rotate it toward the roller until you hear it snap into place.

Figure 1-7 Reinstall the separation roller

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Document feeder pickup roller assembly

CAUTION: Skin oils on the roller can cause paper pickup problems. Wash your hands before handling the assembly.

1.Open the jam-access cover.

Figure 1-8 Open the jam-access cover

2.Locate the separation pad at the end of the document feeder input tray, press down on the pad, and then slide the pad toward the input tray to remove it from the assembly.

Figure 1-9 Remove the document feeder pickup roller assembly

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Pickup roller and separation pad (Tray 1)

The roller must be rotated into the service position to remove it.

CAUTION: Avoid touching the spongy roller surface unless you are going to replace the roller. Skin oils on the roller can cause paper pickup problems.

NOTE: Always replace the separation pad when replacing the pickup roller.

1.Turn the product on, and wait for it to reach the Ready state. Perform the following steps to rotate the roller to the service position.

NOTE: If you have removed Tray 2 to service the product, reinstall the tray before turning the power on.

TIP: The following steps rotate the engine pickup roller and the Tray 1 pickup roller into the service position.

a.Open the 2ndary service menu. See Accessing the 2ndary service menu on page 4

b.Use the arrow buttons to select Pick Roller, and then press the OK button. Touch the OK button again to confirm that you want the roller to rotate.

c.Listen for the roller to rotate. When the roller is done rotating, unplug the power cable.

NOTE: Failure to unplug the product at this point will result in the roller being in the incorrect position for the repair procedure.

d.Remove Tray 2.

e.Perform the remaining steps in this procedure to remove the roller. After replacing the roller, plug the power cable into the product, and then use the power button to turn the power on.

2.Lower the Tray 1 paper pickup assembly by pushing down on the edges of the assembly.

Figure 1-10 Remove the Tray 1 pickup roller (1 of 3)

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3.Carefully raise the front of the product.

CAUTION: Do not lift the product grasping the front door and Tray 2 cavity.

Figure 1-11 Raise the front of the product

4.Release two tabs, and then rotate the roller away from the product to remove it.

Figure 1-12 Remove the Tray 1 pickup roller (3 of 3)

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5.Release the retainer tabs, and then remove the separation pad from the base.

NOTE: The separation pad base can easily be dislodged when the pad is removed. If the base is dislodged, do not loose the spring under the base (it is not captive).

Figure 1-13 Remove the Tray 1 separation pad

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HP LaserJet Pro Color MFP M476 Repair Manual and Troubleshooting Manual

Scanner and document feeder

Scanner assembly

1.Remove the right cover. See Right cover on page 25.

2.Disconnect one ground cable (callout 1), one connector (callout 2), and three FFCs (callout 3).

NOTE: Use a small slotted (flat head) screwdriver to release the ferrite and expose the FFC.

WARNING! The ferrite and cable are fragile. Take care to not damage them when releasing the ferrite.

Figure 1-14 Disconnect the ground cable, connector, and FFCs

3.Remove four screws (callout 1).

Figure 1-15 Remove four screws

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