Copyright Information Warranty Trademark Credits © 2000 Hewlett-Packard Company The information contained in this document is subject to change without notice. CompuServe™ is a U.S. trademark of CompuServe, Inc. All Rights Reserved. Reproduction, adaptations, or translation without prior written permission is prohibited except as allowed under copyright laws. MS-DOS ® is a U.S. registered trademark of Microsoft Corporation. Hewlett-Packard makes no warranty of any kind with respect to this information. HEWLETT-PACKARD SPECIFICALLY DISCLAIMS THE IMPLIED WARRANTY OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

Photoshop™ and PostScript ® are registered trademarks of Adobe Systems Incorporated. Part number C7096-90967 First edition, April 2000 TrueType™ is a U.S. trademark of Apple Computer, Inc. Printed in USA UNIX ® is a registered trademark in the United States and other countries, licensed exclusively through X/Open Company Limited. Hewlett-Packard shall not be liable for any direct, indirect, incidental, consequential, or other damage alleged in connection with the furnishing or use of this information. Safety Information NOTICE TO U.S. GOVERNMENT USERS: RESTRICTED RIGHTS COMMERCIAL COMPUTER SOFTWARE:

“Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c) (1)(ii) of the Rights in Technical Data Clause at DFARS 52.227-7013.” WARNING Electrical Shock Hazard To avoid electrical shock, use only supplied power cords and connect only to properly grounded (3-hole) wall outlets. Hewlett-Packard Company 11311 Chinden Boulevard Boise, Idaho 83714 USA

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Table of Contents 1 Product information Chapter contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21 Printer features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24 Site requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 Media requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29 Identification (model and serial numbers) . . . . . . . . . . . . . . . . .

.38 Printer Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39 Safety information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 2 Service approach Chapter contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Parts and supplies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .61 Ordering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62 Technical assistance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.64 Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69 3 Operational overview Chapter contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 Verifying package contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .73 Verifying the cables are installed. . . . . . . . . . . . . . . . . . . . . . . . . .74 Connecting the printer to the network . . . . . . . . . . . . . . . . . . . . . .76 Changing the printer control panel overlay . . . . . . . . . . . . . . . . . .79 Printer control panel layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80 Menu maps . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . .82 Selecting the display language . . . . . . . . . . . . . . . . . . . . . . . . . . .97 Installing the consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .98 Configuring input trays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103 Verifying the printer is installed correctly. . . . . . . . . . . . . . . . . . .105 Verifying DIMM installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . .106 Duplex registration (HP Color LaserJet 8550). . . . . . . . . . . . . . .107 Booklet printing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.109 HP TonerGauge (HP Color LaserJet 8550) . . . . . . . . . . . . . . . .110 EN 3

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4 Printer maintenance Chapter contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .111 Cleaning procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113 Printer consumables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .118 5 Theory of operation Chapter contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135 Color theory. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .138 Image formation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

.141 Consumable detection mechanisms . . . . . . . . . . . . . . . . . . . . . .154 Electrical systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .164 Mechanical systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169 Paper path. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .178 Printer timing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192 EPH controller board. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199 Duplexer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .199 2,000-sheet input unit . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . .199 Multi-bin mailbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .205 3,000-sheet stapler/stacker. . . . . . . . . . . . . . . . . . . . . . . . . . . . .211 6 Removal and replacement Chapter contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .217 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .222 Maintenance units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .224 Doors and covers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .225 Top assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . .245 Front assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .251 Left assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .253 Right assemblies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .261 Rear assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .270 2,000-sheet input unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .298 Multi-bin mailbox . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .314 3,000-sheet stapler/stacker and 3,000-sheet stacker . . . . . . . . .338 4 Contents EN

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