hp color LaserJet 2550 series
hp color LaserJet 2550 series printer

User Guide

Copyright and License 2004 Copyright Hewlett-Packard Development Company, LP Reproduction, adaptation, or translation without prior written permission is prohibited, except as allowed under the copyright laws. The information contained in this document 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 Q3702-90952 Edition 1, 6/2004
Trademark Credits Adobe Photoshop and PostScript are trademarks of Adobe Systems Incorporated. CorelDRAW is a trademark or registered trademark of Corel Corporation or Corel Corporation Limited. Microsoft, Windows, MS-DOS, and Windows NT are U.S. registered trademarks of Microsoft Corporation. Netscape and Netscape Navigator are U.S. trademarks of Netscape Communications Corporation. TrueType is a U.S. trademark of Apple Computer, Inc. UNIX is a registered trademark of The Open Group. ENERGY STAR and the ENERGY STAR logo are U.S. registered marks of the United States Environmental Protection Agency. Details on the proper use of the marks are explained in the "Guidelines for Proper use of the ENERGY STAR Name and International Logo."

HP customer care

Online services for 24-hour access to information by using a modem or Internet connection World Wide Web: Updated HP printer software, product and support information, and printer drivers in several languages can be obtained from http://www.hp.com/support/clj2550. (The site is in English.) Online troubleshooting tools HP Instant Support Professional Edition (ISPE) is a suite of web-based troubleshooting tools for desktop computing and printing products. ISPE helps you quickly identify, diagnose, and resolve computing and printing problems. The ISPE tools can be accessed from http://instantsupport.hp.com. Telephone support Hewlett-Packard provides free telephone support during the warranty period. When you call, you will be connected to a responsive team that is waiting to help you. For the telephone number for your country/region, see the flyer that came in the box with the product, or visit http://www.hp.com/support/callcenters. Before calling HP, have the following information ready: product name and serial number, date of purchase, and description of the problem. You can also find support on the Internet at http://www.hp.com. Click the support & drivers block. Software utilities, drivers, and electronic information Go to http://www.hp.com/go/clj2550_software. (The site is in English, but printer drivers can be downloaded in several languages.) For information over the telephone, see the flyer that came in the box with the printer. HP direct ordering for accessories or supplies Order supplies from the following websites: United States: http://www.hp.com/sbso/product/supplies Canada: http://www.hp.ca/catalog/supplies Europe: http://www.hp.com/supplies Asia-Pacific: http://www.hp.com/paper/ Order accessories from http://www.hp.com/accessories. For more information, see Accessories and ordering information. To order supplies or accessories over the telephone, call the following numbers: United States: (1) (800) 538-8787 Canada: (1) (800) 387-3154 To find the phone numbers for other countries/regions, see the flyer that came in the box with the printer. HP service information To locate HP-Authorized Dealers in the United States or Canada, call (1) (800) 243-9816 (United States) or (1) (800) 387-3867 (Canada). Or, go to http://www.hp.com/go/ cposupportguide. For service for your HP product in other countries/regions, call the customer support number for your country/region. See the flyer that came in the box with the printer.

HP service agreements Call: 1-800-HPINVENT [(1) (800) 474-6836 (U.S.)] or (1) (800) 268-1221 (Canada). Out-of-Warranty Service: (1) (800) 633-3600. Extended Service: Call 1-800-HPINVENT [(1) (800) 474-6836 (U.S.)] or (1) (800) 268-1221 (Canada). Or, go to the HP Supportpack and Carepaq Services Web site at http://www.hpexpress-services.com/10467a. HP Toolbox To check the printer status and settings and to view troubleshooting information and online documentation, use the HP Toolbox software. You can view the HP Toolbox when the printer is directly connected to your computer or when it is connected to a network. You must have performed a complete software installation to use the HP Toolbox. See Managing the printer.

Table of contents

1 Printer basics
Quick access to printer information...2 User guide links....2 Where to look for more information...2 Printer configurations....4 HP color LaserJet 2550L....4 HP color LaserJet 2550Ln...4 HP color LaserJet 2550n....5 Printer features....6 Printer parts....9 Interface ports....9 Software.....11 Software and supported operating systems...11 Software tips.... Software for Windows...12 Software for Macintosh.... Uninstalling the printing software...14 Print-media specifications...17 General guidelines...17 Paper and print media....17 Printing and storage environment...18 Envelopes.... Labels....20 Transparencies..... Supported media weights and sizes...21

2 Control panel

Control panel features....23 Understanding Supplies Status...24 Understanding Printer Status...24

3 Printing tasks

Loading trays.....28 Loading tray 1.... Loading optional tray 2....29 Loading optional tray 3....31 Controlling print jobs....33 About printing by Source versus by Type or Size..33 Maximizing print speed for letter-size paper...35 Gaining access to printer driver settings...35 Features in the printer driver....36 Selecting an output location.... Printing on special media.... Printing on envelopes...42
Printing on labels....43 Printing on transparencies... Printing on glossy paper....45 Printing on HP LaserJet Tough paper...46 Printing on custom-sized print media or cardstock...46 Printing on letterhead or preprinted forms..47 Printing on both sides (duplexing manually)...48 To duplex manually....48 Canceling a print job....50

Environmental Product Stewardship program...141 Protecting the environment...141 Ozone production....141 Energy consumption... HP LaserJet printing supplies....141 Material safety data sheet.... Declaration of conformity....144 Country-/region-specific safety statements...145 Laser safety statement....145 Canadian DOC statement....145 Korean EMI statement.... Finnish laser statement...146
Appendix E Working with memory
Printer memory.....148 Installing memory and font DIMMs....149 To install memory and font DIMMs...149 Checking DIMM installation...151 To check DIMM installation....151 Enabling memory....152 To enable memory for Windows...152 To enable memory for Mac OS...152 Enabling the language-font DIMM...153 To enable fonts for Windows...153

Printer basics

This section provides information about the following topics: Quick access to printer information Printer configurations Printer features Printer parts Software Print-media specifications
Quick access to printer information

User guide links

Printer parts Control panel features Problem solving
Where to look for more information
Several references are available for use with this printer. See http://www.hp.com/support/ clj2550.

Setting up the printer

Getting started guideProvides step-by-step instructions for installing and setting up the printer.
hp color LaserJet 15502550 series
HP Jetdirect Administrator's GuideContains instructions to configure and troubleshoot the HP Jetdirect print server. This guide is included with printers that come with an HP Jetdirect print server.
Accessory and supplies installation guidesThese guides provide step-by-step instructions for installing the printer accessories and supplies.

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Chapter 1 Printer basics

Using the printer

User guideContains detailed information for using the printer and troubleshooting problems. This guide is available on the CD-ROM that came with the printer. It is also available through the HP Toolbox software.
Online HelpContains information about printer options that are available from within the printer drivers. To view a Help file, open the online Help through the printer driver.
HTML (online) user guideContains detailed information for using the printer and troubleshooting problems. Go to http://www.hp.com/support/clj2550. After connecting, select Manuals.

Printer configurations

Thank you for purchasing the HP color LaserJet 2550 series printer. The printer is available in the following configurations.

Grain Moisture content Smoothness
For complete print-media specifications for all HP LaserJet printers, see the HP LaserJet Printer Family Print Media Guide. To download the guide in PDF format, go to http://www.hp.com/support/ljpaperguide.
Printing and storage environment
Ideally, the printing and media-storage environment should be at or near room temperature, and not too dry or too humid. Remember that paper is hygroscopic; it absorbs and loses moisture rapidly. Heat works with humidity to damage paper. Heat causes the moisture in paper to evaporate, while cold causes it to condense on the sheets. Heating systems and air conditioners remove most of the humidity from a room. As paper is opened and used, it loses moisture, causing streaks and smudging. Humid weather or water coolers can cause the humidity to increase in a room. As paper is opened and used it absorbs any excess moisture, causing light print and dropouts. Also, as paper loses and gains moisture it can distort. This issue can cause jams. As a result, paper storage and handling are as important as the paper-making process itself. Paper storage environmental conditions directly affect the feed operation and print quality. Care should be taken not to purchase more paper than can be easily used in a short time (about three months). Paper stored for long periods can experience heat and moisture extremes, which can cause damage. Planning is important to prevent damage to a large supply of paper. Unopened paper in sealed reams can remain stable for several months before use. Opened packages of paper have more potential for environmental damage, especially if they are not wrapped with a moisture-proof barrier. The media-storage environment should be properly maintained to ensure optimum printer performance. The required condition is 20 to 24 C (68 to 75 F), with a relative humidity of 45 percent to 55 percent. The following guidelines should be helpful when evaluating the paper's storage environment: Print media should be stored at or near room temperature. The air should not be too dry or too humid (to moderate the hygroscopic properties of paper). The best way to store an opened ream of paper is to rewrap it tightly in its moistureproof wrapping. If the printer environment is subject to extremes, unwrap only the amount of paper to be used during the day's operation to prevent unwanted moisture changes. Avoid storing paper and print media near heating and air conditioning vents or near windows and doors that are frequently open.

For more information, see Printing on labels.

Transparencies

Use only tray 1 to print on transparencies. Select Transparencies from the Print dialog box or the printer driver. The printer supports printing on color transparencies. Use only transparencies that are recommended for use in laser printers.
Transparencies that are used in the printer must be able to withstand 210 C (410 F), which is the printer fusing temperature. CAUTION To avoid damage to the printer, use only transparencies that are recommended for use in laser printers. See Accessories and ordering information. For more information, see Printing on transparencies.
Supported media weights and sizes
This section contains information about the sizes, weights, and capacities of paper and other print media that each tray supports. Tray 1 specifications
Tray 1 Paper Dimensions1 Minimum: 76 by 127 mm (3 by 5 inches) Maximum: 216 by 356 mm (8.5 by 14 inches) Glossy paper HP Cover paper4 Transparencies and opaque film Labels3 Envelopes Same as the preceding listed minimum and maximum sizes. 75 to 120 g/m2 (20 to 32 lb) 203 g/m2 (75 lb cover) Thickness: 0.10 to 0.13 mm (3.9 to 5.1 mils) Thickness: up to 0.23 mm (up to 9 mils) Up to 90 g/m2 (16 to 24 lb) Maximum stack height: 12 mm (0.47 inches) 50 (typically) 50 (typically) 50 (typically) Up to 10 Weight 60 to 177 g/m2 (16 to 47 lb) Capacity2 Up to 125 sheets of 75 g/m2 (20 lb) paper
1 The printer supports a wide range of standard and custom sizes of print media. Check the printer driver for supported sizes. 2 Capacity can vary depending on media weight and thickness, and environmental conditions. 3 Smoothness: 100 to 250 (Sheffield). 4 Hewlett-Packard does not guarantee results when printing with other types of heavy paper.
Optional tray 2 specifications
Optional tray 2 (250-sheet tray) Letter A4 A5 B5 (ISO) B5 (JIS) Executive Legal 8.5 by 13 inches
Dimensionsby 279 mm (8.5 by 11 inches) 210 by 297 mm (8.3 by 11.7 inches) 148 by 210 mm (5.8 by 8.3 inches) 176 by 250 mm (6.9 by 9.9 inches) 182 by 257 mm (7.2 by 10 inches) 191 by 267 mm (7.3 by 10.5 inches) 216 by 356 mm (8.5 by 14 inches) 216 by 330 mm (8.5 by 13 inches)

To print from Windows

1. Make sure that print media is loaded in the printer. 2. On the File menu, click Page Setup or a similar command. Make sure that the settings are correct for this document. 3. From the File menu, click Print, Print Setup, or a similar command. The Print dialog box opens. 4. Select this printer and change settings as necessary. Do not change any settings, such as page size or orientation, that you set in the Page Setup dialog box. 5. If this print job is for a standard size and weight of paper, you probably do not need to change the Source is (tray), Type is, or Size is settings, and you can go to step 7. Otherwise, go to step 6. 6. If this print job is to be printed on a non-standard size or weight of paper, select how the printer pulls paper. To print by Source (tray), select the tray in the Print dialog box, if possible. To print by Source (tray) when this setting is not available in the Print dialog box, click Properties, and on the Paper tab, select the tray in the Source is field. To print by Type or Size, click Properties and, on the Paper tab, select the type or size in the Type is or Size is field. (For some paper, such as letterhead, you will set both the Type and Size.) Always print by Type for special print media such as labels or transparencies.
7. If you have not yet done so, click Properties. The printer driver opens. 8. On the various tabs, set any settings that you want that did not appear in the Page Setup or Print dialog box. For more information about printer-driver settings, see Features in the printer driver. 9. By default, the printer prints to the top output bin, which is the best location for most print jobs, including transparencies. For labels, heavy paper, or other special print media, lower the rear output door on the printer. 10. Select the Print command to print the job.
To print from the Macintosh OS
1. Make sure that paper is loaded in the printer. 2. On the File menu, click Page Setup. 3. Make sure that this printer is selected on the Format for pop-up menu. 4. Select the size of paper onto which you are printing. 5. Select the Orientation and Scale, if necessary, and click OK. 6. On the File menu, click Print. 7. Use one of the following methods to select the Source (tray) from which you want to print or select the Type of media onto which you want to print. Always print by Type for special print media such as labels or transparencies. Mac OS 9.1: On the General pop-up menu, select the tray or type of media from the Paper Source pop-up menu. Mac OS X: On the Paper Feed pop-up menu, select the tray or type of media.

To ensure full availability and/or accuracy of printing features (such as remaining supply status), use genuine HP supplies. If you believe you purchased a genuine HP supply, go to http://www.hp.com/go/ anticounterfeit. Imaging drum is a non-HP imaging drum The imaging-drum light is blinking and the Attention light is on. The printer stops printing. A non-Hewlett-Packard supply has been detected. Although HP supports customer choice, HP cannot guarantee the quality or reliability of non-HP supplies. Service or repairs required as a result of using a non-Hewlett-Packard supply are not covered under the printer warranty. If you want to use this non-HP print cartridge, press printing. (CANCEL JOB) to continue

Printer Status lights

The following section describes the meaning of the light patterns in the Printer Status area. Information about the printer status also appears in the HP Toolbox (For more information, see HP Toolbox.)
Light pattern All control panel lights cycling
Error and recommended action Startup All control panel lights cycle one after another. Pressing buttons has no effect until the printer is in the Ready state.
Error and recommended action Ready The Ready (green) light is on and the printer is ready to print. No action is needed. Pressing (GO) prints a Demo page.
Pressing (GO) and (CANCEL JOB) simultaneously prints a Configuration page and a Supplies Status page, and also an HP Jetdirect page if an HP Jetdirect print server is installed.
Processing The Ready light is blinking. The printer is receiving or processing data. (CANCEL JOB) cancels the current job. One or two pages might print Pressing as the printer clears the print job. The printer returns to the Ready state (Ready light on) after the job has been canceled.
Attention error The Attention light is blinking in these situations: The top cover is open. The printer is out of print media. The printer has a jam.
For the first cause, close the top cover. For the second cause, load print media. For the last cause, open and close the top cover after you resolve the problem. If the problem is not resolved, the Attention light continues to blink. Interaction state The Go light is blinking. The top cover has been opened and then closed, or you pressed (ROTATE CAROUSEL). Pressing (GO) returns the printer to the
Ready state. If you do not press the Ready state on its own. Pressing cartridge to the top position.

The toner smears easily when touched.
In the printer driver, select the Paper tab and set Type is to match the type of media on which you are printing. Print speed might be slower if you are using heavy paper. Check the paper type and quality. Use a different paper, such as high-quality paper intended for laser printers. See Print-media specifications. Clean the inside of the printer. See Cleaning the printer. The fuser might be damaged. Contact HP Customer Care. See HP customer care or the support flyer that came in the printer box. If the problem is not resolved, see If the problem is not resolved.
Marks repeatedly appear at even intervals on the printed side of the page.
In the printer driver, select the Paper tab and set Type is to match the type of paper on which you are printing. Print speed might be slower if you are using heavy paper. Clean the printer. See Cleaning the printer. Use the tools on the Troubleshooting tab of the HP Toolbox to correct the problem. The imaging drum might be defective. Replace the imaging drum. The fuser might be damaged. Contact HP Customer Care. See HP customer care or the support flyer that came in the printer box. If the problem is not resolved, see If the problem is not resolved.
Marks repeatedly appear at even intervals on the unprinted side of the page.
Internal parts might have toner on them. The problem will likely correct itself after a few more pages. Clean the printer. See Cleaning the printer. The fuser might be damaged. Contact HP Customer Care. See HP customer care or the support flyer that came in the printer box. If the problem is not resolved, see If the problem is not resolved.
The printed page contains misformed characters.
If characters are improperly formed so that they produce hollow images, the paper might be too slick of a paper, such as a photo, glossy, or coated paper. Use a different paper, such as high-quality paper intended for laser printers. See Print-media specifications. If characters are improperly formed so that they produce a wavy effect, the laser scanner might need service. Verify that the problem also occurs on the Configuration page. If so, contact HP Customer Care. See HP customer care or the support flyer that came in the printer box. If the problem is not resolved, see If the problem is not resolved.
The printed page is curled or wavy.
Turn over the stack of paper in the tray. Also try rotating the paper 180 degrees in the input tray. Set the correct Type in the printer driver. Heavier paper might take longer to print. Open the rear output door to print to the straight-through paper path. Check the paper type and quality. Both high temperature and humidity will cause paper curl. Use a different paper, such as high-quality paper intended for laser printers. See Print-media specifications. If the problem is not resolved, see If the problem is not resolved.

HP Premium Cover paper

Q2414A (A4) 100 sheets
HP Printing paper HP Printing paper HP Multipurpose paper HP Multipurpose paper HP LaserJet Tough paper
HPP1122 (letter) CHP210 (A4) HPM1120 (letter) HPM1420 (legal) Q1298A (letter)

HP LaserJet Tough paper

Q1298B (A4)
HP High Gloss laser paper
Q2419A (letter) 200 sheets
Product name HP High Gloss laser paper
Description High-gloss finish coating on both sides. Use for brochures, catalogs, photographs, and whenever a high-gloss finish is desired. Satin finish coating on both sides. 120 g/m2 (32 lb) Satin finish coating on both sides. 120 g/m2 (32 lb) Satin finish coating on both sides. 105 g/m2 (28 lb) Satin finish coating on both sides. 105 g/m2 (28 lb) Use color transparencies for full-color printing. Use color transparencies for full-color printing.
Part number Q2421A (A4) 200 sheets
HP Soft Gloss laser paper (heavy) HP Soft Gloss laser paper (heavy) HP Soft Gloss laser paper HP Soft Gloss laser paper HP color LaserJet transparencies HP color LaserJet transparencies
Q4179A (letter) 200 sheets C4179B (A4) 200 sheets Q2415A (letter) 500 sheets Q2417A (A4) 500 sheets C2934A (letter) 50 sheets C2936A (A4) 50 sheets

User-replaceable parts

Product name Fuser Description Replace when print-quality issues remain after you have cleaned the engine and tried all troubleshooting measures. (See Cleaning the printer and Solving print-quality problems.) Replace when the printer is picking up multiple sheets or no sheets. Trying different paper did not resolve the problem. Part number Contact HP Customer Care to order parts.
Separation pad and pick-up rollers
Contact HP Customer Care to order parts.
Supplementary Documentation
A printed copy of this user guide is available in the following languages. User guides
Language English Arabic Chinese, simplified Czech Danish Dutch Finnish French German Hebrew Hungarian Italian Korean Norwegian Portuguese, Brazilian Polish Russian Spanish, Castilian Swedish Thai Traditional Chinese Turkish Part number Q3702-90905 Q3702-90901 Q3702-90917 Q3702-90902 Q3702-90903 Q3702-90904 Q3702-90906 Q3702-90907 Q3702-90908 Q3702-90909 Q3702-90910 Q3702-90911 Q3702-90912 Q3702-90913 Q3702-90914 Q3702-90915 Q3702-90916 Q3702-90918 Q3702-90919 Q3702-90921 Q3702-90920 Q3702-90922

Service and support

Hewlett-Packard limited warranty statement
HP PRODUCT HP color LaserJet 2550L, 2550Ln, 2550n DURATION OF LIMITED WARRANTY 1 year, Return to Authorized Service Center

Service information form

WHO IS RETURNING THE EQUIPMENT? Person to contact: Alternate contact: Return shipping address: Special shipping instructions: Date: Phone: Phone:
WHAT ARE YOU SENDING? Model name: Model number: Serial number:
Please attach any relevant printouts. Do NOT ship accessories (manuals, cleaning supplies, etc.) that are not required to complete the repair. HAVE YOU REMOVED THE PRINT CARTRIDGES AND IMAGING DRUM? You must remove them before shipping the printer, unless a mechanical problem prevents you from doing so. Yes. No, I cannot remove them.
WHAT NEEDS TO BE DONE? (Attach a separate sheet if necessary.) 1. Describe the conditions of the failure. (What was the failure? What were you doing when the failure occurred? What software were you running? Is the failure repeatable?)
2. If the failure is intermittent, how much time elapses between failures? 3. If the unit connected to any of the following, give the manufacturer and model number. Personal computer: 4. Additional comments: Modem: Network:
HOW WILL YOU PAY FOR THE REPAIR? Under warranty Purchase/received date:
(Attach proof of purchase or receiving document with original received date.) Maintenance contract number: Purchase order number: Except for contract and warranty service, a purchase order number and/or authorized signature must accompany any request for service. If standard repair prices do not apply, a minimum purchase order is required. Standard repair prices can be obtained by contacting an HP-authorized repair center. Authorized signature: Billing address: Special billing instructions: Phone:

Specifications

Printer specifications

Physical specifications

Product HP color LaserJet 2550L printer without optional trays HP color LaserJet 2550n printer with tray 2 (250-sheet) HP color LaserJet 2550n printer with tray 2 and optional tray 3 (500-sheet) Height 325 mm (12.80 in) Depth 451 mm (17.76 in) Width 482 mm (18.98 in) Weight 21.5 kg (47.5 lbs)

376 mm (14.80 in)

451 mm (17.76 in)

482 mm (18.98 in)

23.9 kg (52.7 lbs)

512 mm (20.16 in)

29.3 kg (64.6 lbs)

Supplies specifications

Imaging-drum life (based on 5 percent coverage) 20,000 pages when printing only in black 5,000 pages when printing in color 6,000 to 8,000 pages is the average life Print-cartridge life (based on 5 percent coverage) Black: 5,000 pages Yellow, cyan, and magenta: 2,000 pages each (HP color LaserJet 2550L printer) Yellow, cyan, and magenta: 4,000 pages each (HP color LaserJet 2550Ln and 2550n printers)

Electrical specifications
Item Power supply 110-volt models 115 to 127 V (+/- 10 %) 50 to 60 Hz (+/- 2 Hz) Power consumption (typical) During printing (color) During printing (black and white) During standby Off mode Heat output Idle Minimum recommended circuit capacity 51 BTU/hr 12 A 61 BTU/hr 6A 224 W (average) 400 W (average) 15 W (average) 0 W (average) 217 W (average) 400 W (average) 19 W (average) 0 W (average) 220-volt models 220 to 240 V (+/- 10 %) 50 to 60 Hz (+/- 2 Hz)
Power requirements are based on the country/region where the printer is sold. Do not convert operating voltages. This will damage the printer and void the product warranty. Environmental specifications
Recommended1 (printer and print cartridge) Temperature Relative humidity
Operatingto 32.5 C (59 to 90.5 F) 10 to 80 percent
Storage1 -20 to 40 C (-4 to 104 F) 95 percent or less
20 to 27 C (68 to 81 F) 20 to 70 percent
Values are subject to change. See http://www.hp.com/support/clj2550 for current information.
Acoustic emissions (HP color LaserJet 2550 series)
Sound Power Level Printing (20 ppm) SPL-Bystander Position Printing (20 ppm)
Declared per ISO 92961 LWAd = 6.6 Bels (A) [66 dB (A)] Declared per ISO 92961 LpAm = 52 dB(A)

Regulatory information

Introduction
This section contains the following regulatory information: FCC regulations Environmental Product Stewardship program Material safety data sheet Declaration of conformity Laser safety statement Canadian DOC statement Korean EMI statement Finnish laser statement

FCC regulations

This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy. If this equipment is not installed and used in accordance with the instructions, it may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation; the presence of interference can be determined by turning the equipment off and on. If this equipment does cause harmful interference to radio or television communications, the user is encouraged to try to correct the interference by one or more of the following measures: Note Reorient or relocate the receiving antenna. Increase distance between equipment and receiver. Connect equipment to an outlet on a circuit different from that to which the receiver is located. Consult your dealer or an experienced radio/television technician.

Material safety data sheet
Material Safety Data Sheets (MSDS) can be obtained by contacting the HP LaserJet Supplies website at http://www.hp.com/hpinfo/community/environment/productinfo/safety.htm. Extended warranty HP SupportPack provides coverage for the HP hardware product and all HP supplied internal components. The hardware maintenance covers a three-year period from the date of the HP product purchase. The customer must purchase HP SupportPack within 90 days of the HP product purchase. For more information, contact the HP Customer Care Service and HP Customer Support Group. See HP customer care. Spare parts and supplies availability Spare parts and consumable supplies for this product will be available for at least five years after production has stopped. For more information On HPs environmental programs, including: Product environmental profile sheet for this and many related HP products HPs commitment to the environment HPs environmental management system HPs end-of-life product return and recycling program Material Safety Data Sheets
See: http://www.hp.com/go/environment or http://www.hp.com/hpinfo/community/environment
Declaration of conformity
Declaration of Conformity according to ISO/IEC Guide 22 and EN 45014 Manufacturer's Name: Manufacturer's Address: declares, that the product Product Name: Regulatory Model Number4): Product Options: conforms to the following Product Specifications: Safety: IEC 60950:1999 / EN60950: 2000 IEC 60825-1:1993 +A1: 1997 +A2:2001 / EN 60825-1:1994 +A11:1996 +A2:2001 (Class 1 Laser/LED Product) GB4943-2001 CISPR 22:1997 / EN 55022:1998 Class B1) 3) EN 61000-3-2:1995 / A14 EN 61000-3-3:1995/ A1 EN 55024:1998 FCC Title 47 CFR, Part 15 Class B2) / ICES-003, Issue 3/ GB9254-1998, GB17625.1-1998 / CNS 13438 HP color LaserJet 2550L/2550Ln/2550n BOISB-0305-00. Including: Q3709A Optional 250-sheet input tray; Q3710A Optional 500-sheet input tray ALL Hewlett-Packard Company 11311 Chinden Boulevard Boise, Idaho 83714-1021, USA
Supplementary Information: The product herewith complies with the requirements of the EMC Directive 89/336/EEC and the Low Voltage Directive 73/23/EEC, and carries the CE-Marking accordingly. 1) The product was tested in a typical configuration with Hewlett-Packard Personal Computer Systems. Compliance testing of product to standard with exception of Clause 9.5, which is not yet in effect. 2) This Device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation. 3) This product includes LAN (Local Area Network) options. When the interface cable is attached to LAN connectors, the product meets the requirements of EN55022 & CNS13438 Class A in which case the following applies: "Warning This is a class A product. In a domestic environment this product may cause radio interference in which case the user may be required to take adequate measures." 4) For regulatory purposes, this product is assigned a Regulatory model number. This number should not be confused with the product name or the product number(s). Boise, Idaho , USA 1 April, 2004 For regulatory topics only: Australia Contact: European Contact: USA Contact: Product Regulations Manager, Hewlett-Packard Australia Ltd., 31-41 Joseph Street Blackburn, Victoria 3130, Australia Your Local Hewlett-Packard Sales and Service Office or Hewlett-Packard GmbH, Department HQ-TRE / Standards Europe, Herrenberger Strasse 140 , D-71034, Bblingen (FAX: +49-7031-14-3143) Product Regulations Manager, Hewlett-Packard Company, PO Box 15, Mail Stop 160 Boise, Idaho 83707-0015, (Phone: 208-396-6000)

Printer memory

The HP color LaserJet 2550 series printer has one dual inline memory module (DIMM) slot for upgrading the printer capabilities with the following options: More printer memory. DIMMs are available in 32, 64, and 128 MB for a maximum of 160 MB. DIMM-based accessory fonts, macros, and patterns.
You might want to add more memory to the printer if you often print complex graphics or PS documents, or use many downloaded fonts. Additional memory also allows the printer to print multiple, collated copies at the maximum speed. Before ordering additional memory, see how much is currently installed by printing a (GO) and (CANCEL JOB) simultaneously, or use the HP Configuration page. [Press Toolbox.] To order DIMMs, see Accessories and ordering information. Single inline memory modules (SIMMs) used on previous HP LaserJet printers are not compatible with the printer.
Installing memory and font DIMMs
You can install more memory for the printer, and you can also install a font DIMM to print characters for languages such as Chinese, or for the Cyrillic alphabet. CAUTION Static electricity can damage DIMMs. When handling DIMMs, wear an antistatic wrist strap, or frequently touch the surface of the DIMM antistatic package and then touch bare metal on the printer.
To install memory and font DIMMs
1. (GO) and (CANCEL JOB) simultaneously. (A Print a Configuration page by pressing Supplies Status page and possibly an HP Jetdirect Configuration page also print.) If the Configuration page does not print in your language, see Special pages.
2. After the Configuration page prints, turn the printer off and disconnect the power cable.
3. On the right side of the printer, open the DIMM door.
4. Open the second DIMM door.
5. Release the locks on each side of the DIMM slot.
6. Remove the DIMM from the antistatic package.
7. Holding the DIMM by the edges as shown in the illustration, align the notches on the DIMM with the DIMM slot.
8. Firmly press the DIMM straight into the slot. Firmly close the locks on each side of the DIMM until they snap into place.
9. Close the two DIMM doors.
10. Reconnect the power cable and turn the printer on.

Troubleshooting
To better help our customers - this HP Laserjet 2550 series troubleshooting page is simply a guide / additional information for your convenience, as you search for assistance in repairing your machine. Although this information is provided for your convenience it is recommended, for the most part, that a technician inspects your office equipment.
It is recommended to consult with a professional when ordering your printer part(s).

Chapter contents

Maintenance
Chapter contents Life expectancies of supplies User-replaceable parts Cleaning the printer Calibrating the printer Managing supplies
Shop with us while you troubleshoot.
* HP oem parts * HP LaserJet maintenance kits
. * Toners for your printer * HP fuser assembly units * HP fuser kit 110v & 220v

Theory of operation

Chapter contents Introduction Engine control system Laser/scanner system Pickup and feed system Image-formation system
* Parts assemblies for printers * Service maintenance parts * Color laserJet printers * LaserJet printers and parts * Hard to find officejet parts * Hard to find deskjet parts User-friendly SmartSearch!

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Partshere Troubleshooting
Life expectancies of supplies
Inspect supplies when you service the printer. Replace supplies as needed, based on failure or wear, rather than on usage. The following table lists approximate schedules for replacing supplies.
Table 3-1. Life expectancies of supplies
Description Part number Estimated life (in number of pages at 5 percent coverage1) 5,000 Remarks
Print cartridge, black (user replaceable) Print cartridge, cyan (user replaceable) Print cartridge, cyan (user replaceable) Print cartridge, yellow (user replaceable) Print cartridge, yellow (user replaceable) Print cartridge, magenta (user replaceable) Print cartridge, magenta (user replaceable) Imaging drum
Q3960-67901 Q3960-67902 (EMEA) Q3971-67901 Q3971-67902 (EMEA) Q3961-67901 Q3961-67902 (EMEA) Q3972-67901 Q3972-67902 (EMEA) Q3962-67901 Q3962-67902 (EMEA) Q3973-67901 Q3973-67902 (EMEA) Q3963-67901 Q3963-67902 (EMEA) Q3964-67901

Extended-life cartridge

20,000 (black only) 5,000 (color)
The average life is 6,000 to 8,000 pages. Can affect print quality and paper movement. Look for glazing and/or cracks. Can affect document movement. Can affect print quality and document movement. Can affect print quality and document movement. Can affect document movement.

Transfer roller

RF5-4067-000CN

Printer pickup roller

RB3-0160-000CN

Printer separation pad

RF5-4012-000CN
Fuser assembly, 110-127 V)

RG5-7572-000CN

Fuser assembly, 220-240 V)

RG5-7573-000CN

Separation pad, optional trays 2 and 3

RB2-9960-000CN

The estimated print cartridge life is based on letter- or A4-sized paper with an average of 5% toner coverage and a medium density setting. Print cartridge life can be extended further by conserving toner by using draft-mode settings.

User-replaceable parts

Pickup rollers and separation pads are user-replaceable parts.
Replacing the tray 1 pickup roller and separation pad
1. Turn the printer off and disconnect the power cable from the back of the printer.

2. Open tray 1.

3. Find the faceplate cover that is located beneath the pickup roller in tray 1.
4. Grasp both sides of the center tab and pull the cover out of the printer.
5. Squeeze the tab on the idler roller that is located on the right side of the pickup roller. If the tab is not visible, rotate the idler roller so that the tab is toward the front of the printer.

6. Slide the idler roller to the right to separate it from the pickup roller.
7. Squeeze the tab on the idler roller that is located on the left side of the pickup roller. If the tab is not visible, rotate the idler roller so that the tab is toward the front of the printer.
8. Slide the idler roller to the left to separate it from the pickup roller.
9. Press and hold the button that is located on the right side of the pickup roller. Slide the pickup roller slightly to the right, and then pull it off of the shaft.

CAUTION

To prevent the shaft retaining pin from falling out, do not move the remaining hub that is located to the left of the pickup roller. 10. Locate the separation pad beneath the area of the shaft from which the pickup roller was removed.
11. Insert a flatblade screwdriver into the slot under the separation pad. Pry the pad up from the spring-loaded base by twisting the screwdriver until the tabs are separated from the printer.
12. Use one hand to push the spring-loaded base down and then use the other hand to pull the separation pad up and out of the printer.
If you feel resistance when you try to remove the pad, make sure that the tabs are completely separated from the printer. 13. Push the spring-loaded base down and position the new separation pad in the empty slot.
Make sure that the two tabs on the edge of the pad are toward the front of the printer.
14. Snap both sides of the separation pad firmly into place until they click.
If the pad is not straight, or if space exists between the pad and the base, make sure that the tabs on the pad are toward the front of the printer. 15. Hold down the new separation pad. Position the new pickup roller so that the button is on the right side, and the open side of the roller faces down. Make sure that the small ridge on the open side of the roller aligns with the groove in the shaft.
16. Slide the left and right idler rollers inward, against the pickup roller, until the idler rollers click into place.
17. Hold the faceplate cover as shown in the illustration, and align the cover with the rails on the inside of the printer.
18. Grasp both sides of the center tab and insert the cover into the printer until the cover clicks into place. Close tray 1.
Replacing the separation pad in optional tray 2 or in optional tray 3
1. Remove the tray from the printer and place it on a flat surface. Remove any paper from the tray.
2. Locate the separation pad in the base at the inside-front edge of the tray.
3. Press the large metal plate at the bottom of the tray down. Insert a flatblade screwdriver in the slots on each side of the base and push the tabs out of the slots.

In a 250-sheet tray, the plate locks down; in a 500-sheet tray, hold the plate down manually. 4. Pull the separation pad up and out of the tray.
5. Use one hand to position the new separation pad above the empty base. Align the grooves on the sides of the pad with the sides of the base, and then slide the pad down until the tabs snap into the slots on the base.
6. Reload any print media, and then slide the tray into the printer.
7. Reconnect the power cable. Turn the printer on.
8. When the green Ready light is on, press Go to print a Demo page, which verifies that the printer works and that installation is complete.
9. If the page does not print, or to find additional help, go to www.hp.com/support/clj2550. Note If the page does not print, reconnect the power cable. Make sure that the Ready light is on and that no other lights are on or blinking. Make sure that print media is loaded and that all parts are installed correctly.

Cleaning the printer

During the printing process, paper, toner, and dust particles can accumulate inside the printer. Over time, this buildup can cause print-quality problems such as toner specks or smearing.
Use a cleaning page to correct and prevent print-quality problems such as toner specks or smearing.

Figure 3-1.

Smearing

Figure 3-2.

Toner specks

To use a cleaning page

Note The following procedure must be performed from the HP LaserJet Toolbox. To clean the printer when the computer is running an operating system that does not support the HP LaserJet Toolbox, see the Late-Breaking Readme on the CD-ROM, or visit www.hp.com/ support/clj2550. 1. Make sure that the printer is turned on and in the Ready state. 2. Open the HP LaserJet Toolbox. 3. On the Troubleshooting tab, click Maintenance, click Cleaning Page, and then click Print. A page with a pattern prints from the printer. 4. At the printer, remove any print media that might be in tray 1.
5. Remove the page that printed and load it face-down into tray 1 (see Figure 3-3. Loading the cleaning page in tray 1).

Figure 3-3.

Loading the cleaning page in tray 1 6. At the computer, click Clean.

Calibrating the printer

The printer automatically calibrates at various times. You can adjust the calibration settings by using the HP LaserJet Toolbox. Environmental differences, aging print cartridges, aging toner, and an aging imaging drum might cause fluctuations in image density. The printer accounts for this with image stabilization control. The printer automatically calibrates at various times to maintain the highest level of print quality. You can also request a calibration by using the HP LaserJet Toolbox. The printer does not interrupt a print job to calibrate. It waits until the job is complete before calibrating or cleaning. While the printer is calibrating, it pauses printing for the time that is required to complete the calibration.
To calibrate the printer at the printer
Press (GO) and (ROTATE CAROUSEL) simultaneously to start a calibration.
To calibrate the printer from the HP LaserJet Toolbox
Note This procedure applies to Windows operating systems only. Macintosh users should calibrate the printer manually by using the previous procedure. 1. Open the HP LaserJet Toolbox in one of these ways: On the desktop, double-click the HP LaserJet Toolbox icon. On the Start menu, point to Programs, point to HP Color LaserJet 2550, and then click HP LaserJet Toolbox. 2. On the Troubleshooting tab, click Print Quality (on the left side of the screen). 3. Click Calibrate Now.

Managing supplies

For warranty information about these supplies, see Limited warranty for the print cartridges and imaging drum.

Supplies life

The life of the imaging drum depends on the number of black-only or color pages that print jobs require. An HP color LaserJet 2550 series printer imaging drum could last an average of 20,000 pages when printing black-only pages and 5,000 pages when printing color pages. Actual life lies somewhere between these two numbers, depending on the number of blackonly pages you print versus color. The average life is between 6,000 and 8,000 pages. Imaging-drum life is also affected each time the printer calibrates because calibrating causes the imaging drum to rotate. Imaging-drum life is measured in terms of number of rotations rather than number of pages printed. The type and length of print jobs also affects drum life. A series of short print jobs uses more drum life than an equivalent number of pages printed in a single large job. To extend drum life, print multiple copies of a print job at one time rather than sending the same job to the printer multiple times. The life of a print cartridge depends on the amount of toner that print jobs require. When printing text at 5% coverage, black print cartridges last an average of 5,000 pages and cyan, magenta, and yellow print cartridges last an average of 2,000 pages. Extended-life cyan, magenta, and yellow print cartridges last an average of 4,000 pages. (A typical business letter has 5% coverage.) NoteNote The imaging drum and print cartridges for this printer are not compatible with older, similar printer models such as the HP color LaserJet 1500 series printer or the HP color LaserJet 2500 series printer. For longer supplies life, you can order extended-life replacement cyan, magenta, or yellow print cartridges for the HP color LaserJet 2550L printer that last an average of 4,000 pages at 5% coverage.

Checking and ordering supplies
You can check the supplies status by using the printer control panel, printing a Supplies Status page, viewing the HP LaserJet Toolbox, or viewing HP Web Jetadmin. HewlettPackard recommends that you place an order for a replacement print cartridge when you first receive the Low message for a print cartridge. The Low message indicates that approximately two weeks of life remain. When you use a new, authentic HP print cartridge or imaging drum, you can obtain the following types of supplies information: amount of cartridge or drum life remaining estimated number of pages that can be printed number of pages printed other supplies information Note If the printer is connected to the network, you can set the HP LaserJet Toolbox to notify you by e-mail when a print cartridge is low or the imaging drum is near the end of its useful life. If the printer is directly connected to a computer, you can set the HP LaserJet Toolbox to notify you when supplies are low.
To check status and order supplies using the control panel
Do one of the following: Check the supplies status lights on the printer control panel. These lights indicate when a print cartridge or the imaging drum is low or empty. The lights also indicate when a non-HP print cartridge is first installed. See Supplies Status lights to interpret the light patterns. (Go) and (Cancel Job) simultaneously. A Supplies Status page (and the Press Configuration page and, possibly, the HP Jetdirect page) prints. Check the supplies levels on the Supplies Status page. If the supplies levels are low, you can order supplies through your local HP dealer, by telephone, or online. See Parts and diagrams for part numbers. See www.hp.com/go/ ljsupplies to order online.
To check status and order supplies using the HP LaserJet Toolbox
You can configure the HP LaserJet Toolbox to notify you when the supplies are low. You can choose to receive alerts by e-mail or as a pop-up message or taskbar icon. To order supplies by using the HP LaserJet Toolbox, in the Other Links area, click Order supplies. For more information, see Other links.

To check status and order supplies using HP Web Jetadmin
In HP Web Jetadmin, select the printer device. The device status page shows supplies information. To order, use the HP LaserJet Toolbox. Or, see Parts and diagrams.

Storing supplies

Follow these guidelines for storing print cartridges and the imaging drum: Do not remove the print cartridge or imaging drum from its package until you are ready to use it. CAUTION To prevent damage, do not expose the print cartridge or imaging drum to light for more than a few minutes. See Table 1-5. Environmental specifications for operating- and storage-temperature ranges. Store the supply in a horizontal position. Store the supply in a dark, dry location away from heat and magnetic sources.
Replacing and recycling supplies
To install a new HP print cartridge or imaging drum, follow the instructions included in the box that contains the new supply, or see the HP Color LaserJet 2550 Series Getting Started Guide.
To recycle supplies, place the used supply in the box in which the new supply arrived. Use the enclosed return label to send the used supply to HP for recycling. For complete information, see the recycling guide that is included with each new HP supply item. See HP Printing Supplies Returns and Recycling Program information for more information about HP's recycling program.
HP policy for non-HP supplies
Hewlett-Packard Company cannot recommend the use of non-HP supplies, either new or remanufactured. Because they are not HP products, HP cannot influence their design or control their quality. Service or repairs that are required as a result of using a non-HP supply will not be covered under the printer warranty. When you insert a supply into the printer, the printer informs you if the supply is not a genuine HP supply. If you insert a genuine HP supply that has reached the low state from another HP printer, the printer identifies the supply as non-HP. Simply return the supply to the original printer to reactivate HP features and functionality.
Resetting the printer for non-HP supplies
When you install a non-HP print cartridge or imaging drum, the light next to the print cartridge or imaging drum you replaced blinks and the Attention light is on. In order to print with this supply, you must press (Cancel Job) the first time you install this nonHP supply. The status lights will not indicate when this type of supply is low or empty. CAUTION The printer will not stop printing when a non-HP supply is empty. Printer damage can occur if the printer attempts to print with an empty print cartridge or imaging drum. See Uninstalling the printing software.

HP fraud hotline

Call the HP fraud hotline if the supplies status lights indicate that the print cartridge or imaging drum is not an HP product and you think that it is genuine. Hewlett-Packard will help determine if the product is genuine and take steps to resolve the problem. Your print cartridge or imaging drum might not be a genuine HP product if you notice the following issues: You are experiencing a large number of problems with the print cartridge or imaging drum. The print cartridge or imaging drum does not look like an HP product usually does (for example, the pull tab or the box is different). In the United States, call toll-free: 877-219-3183. Outside the United States, you can call collect. Dial the operator and ask to place a collect call to this telephone number: 770-263-4745. If you do not speak English, a representative at the HP fraud hotline who speaks your language will assist you. Or, if someone who speaks your language is not available, a language line interpreter will connect approximately one minute after the beginning of the call. The language line interpreter is a service that translates between you and the representative for the HP fraud hotline.
Chapter contents... Introduction... Engine control system... Laser/scanner system... Pickup and feed system.. Image-formation system...

Introduction

This chapter presents an overview of the relationships between major components in the printer, and includes a detailed discussion of the image-formation system. The following systems are discussed: engine control system laser/scanner system pickup and feed system image-formation system
Figure 4-1. Cross-section of the printer
Description Laser/scanner Developing cylinder Photosensitive drum Primary charging roller Imaging drum
Part number RG5-6880-000CN (contained in print cartridge) (contained in imaging drum) (contained in imaging drum) Q3964A

Ref 18 19

Description Transfer belt Density sensor Primary transfer roller Transfer-belt cleaning roller Registration shutter Pickup roller Tray 1 Separation pad Registration roller Secondary transfer roller Auxiliary transfer-belt cleaning roller Feed belt (8) Carousel Print cartridge
Part number (contained in imaging drum) RH7-7146-000CN (contained in imaging drum) (contained in imaging drum) (contained in imaging drum) RG5-6592-000CN RG5-7585-000CN RF5-4012-000CN RG5-6939-000CN RF5-4067-000CN (contained in imaging drum) RB3-0063-000CN RG5-7592-000CN (several; see Table 7-2. Accessories for part numbers) (contained in fuser) (contained in fuser) (contained in fuser) RG5-7595-000CN (lower) and RG5-6897-000CN (upper)

Fusing film Pressure roller Fuser delivery roller Top output bin delivery roller

Engine control system

The engine control system coordinates all printer functions. It drives the laser/scanner system, the image formation system, and the pickup and feed system. The engine control system contains the following components: Dc controller High-voltage power-supply PCB Low-voltage power unit: Fuser-control circuit Low-voltage power-supply PCB

Figure 4-2.

Engine control system (includes the basic configuration of the printer)
Basic sequence of operation
Operation sequences are controlled by the CPU in the dc controller in the engine control system. Table 4-1. Basic sequence of operation describes engine operations for each period of a print operation.
Table 4-1. Basic sequence of operation
Period WAIT (wait) Duration From the time the power switch is turned on until transfer-belt cleaning is complete. Purpose Clears potential from the drum surface and cleans the transfer belt. Remarks See Figure 4-3. Power-on sequence for a complete description of the WAIT (power-on) period. Also see the General timing charts for detailed information about timing.

STBY (standby)

From the end of the WAIT or LSTR period until either a print command is sent from the formatter or the power is turned off.
Prepares the printer to receive print commands.
Table 4-1. Basic sequence of operation (continued)
Period INTR (initial rotation) Duration From the time of the print command until detection of the HP1 (transfer-belt homeposition detection) signal for the first color. From the end of the INTR period until detection of the transfer-belt home-position signal for the secondary transfer. From the end of the PRINT period until the main motor stops rotating. Purpose Prepares the photosensitive drum for printing. Remarks

PRINT (print)

Forms the image on the photosensitive drum and transfers the toner image to the transfer belt.

LSTR (last rotation)

Transfers the toner image on the transfer belt to the media and delivers the printed media.
After LSTR, the printer returns to STBY.

Power-on sequence

The power-on sequence is represented by the flowchart in Figure 4-3. Power-on sequence.

Figure 4-3.

Motors and fans

Figure 4-4.

Table 4-2. Motors and fans
Reference Description Engaging motor Developing-rotary motor Toner-cartridge motor Fuser motor Main motor Cooling fan

Laser/scanner system

The laser/scanner system receives video signals from the dc controller, and then it converts the signals into latent images on the photosensitive drum. The dc controller controls the laser/scanner.

Figure 4-5.

Pickup and feed system
The pickup and feed system consists of several types of feed rollers and sensors. The dc controller drives the paper and feed system by controlling two motors, two clutches, and the solenoid. Two photo-interrupters (PS1 and PS711) detect media as it passes. If media does not reach or pass each sensor within the specified time period, the dc controller determines that a jam has occurred and alerts the video controller circuit. The following components are identified in Figure 4-6. Pickup and feed system: PS1 fusing-delivery paper sensor PS711 registration paper sensor PS718 tray 1 (multipurpose tray) paper sensor PS720 fuser wrap-jam sensor DCM701 main motor PM702 fuser motor SL92 tray 1 pickup solenoid
CL1 registration clutch CL2 roller-engaging clutch

Figure 4-6.

Paper trays
The dc controller drives the operation sequence of the paper trays. It signals the driver PCB in optional tray 2 (250-sheet paper tray) and in optional tray 3 (500-sheet paper tray). In optional tray 2, the printer main motor drives the tray solenoids. In optional tray 3, each driver PCB controls the motors and solenoids in its paper tray. The following components are identified in Figure 4-7. Optional tray 2 (250-sheet paper tray): DCM701 gear-train motor (printer) SL9 pickup solenoid (optional tray 2)
PS716 paper sensor (optional tray 2) PS717 paper-feed sensor Note Only optional tray 2 is shown; optional tray 3 is similar.

Figure 4-7.

Optional tray 2 (250-sheet paper tray)

Jam detection

The registration sensor (PS711) and the fuser sensor (PS1) detect media that is moving through the printer. If a jam is detected, the dc controller immediately stops the printing process and sends a message to the video controller circuit. A jam can be detected under any of the following conditions: Pickup delay jam. The leading edge of the print media does not reach the registration sensor (PS711) within 1.1 seconds (tray 1), 1.7 seconds (optional tray 2), or 2.8 seconds (optional tray 3). Pickup stationary jam. The registration clutch is on, and the registration sensor (PS711) does not detect the trailing edge of the media within 3.4 seconds after the start of a repickup operation. Fuser wrap-jam. The main CPU detects media inside the fuser front sensor (PS720) when the power is turned on or after the top cover is closed.

Figure 4-15.

Latent-image-formation stage

Step 1: primary charging

A dc bias is applied to the primary charging roller, which transfers a uniform negative potential to the photosensitive drum.

Figure 4-16.

Step 2: laser-beam exposure
The laser beam scans the photosensitive drum to neutralize negative charges on parts of the drum. An electrostatic latent image is formed on the drum where negative charges were neutralized.

Figure 4-17.

Developing stage
The developing cylinder comes in contact with the photosensitive drum to deposit toner onto the electrostatic latent image.
The charges on the exposed area on the drum are shown as positive in Figure 4-18. Developing block. The charges are actually negative, but they are more positive than the charges on the developing cylinder.

Figure 4-18.

Developing block
Step 3: auxiliary developing
The dc bias applied to the blade imports a uniform negative potential to the toner.

Step 4: developing

Toner acquires a negative charge through friction from the developing cylinder and the blade. When the negatively charged toner comes in contact with the drum, the toner adheres to the electrostatic latent image. The image on the drum becomes visible because of the toner.

Figure 4-19.

Step 3: developing

Transfer stage

Step 5: primary transfer
The primary transfer roller, to which a dc positive bias is applied, imparts a positive charge on the transfer belt. The negatively charged toner on the drum is transferred to the positively charged transfer belt. This procedure is repeated for each color (yellow, magenta, cyan, and black). The dc positive bias is increased for each successive color to make sure that all of the colors adhere to the transfer belt.

Figure 4-20.

Step 4: primary transfer
Step 6: secondary transfer
The secondary transfer roller, to which a dc positive bias is applied, imparts a positive charge to the print media. When the print media comes in contact with the transfer belt, the toner is transferred to the print media.

When secondary transfer is complete, a dc negative bias is applied to the secondary transfer roller to prevent toner on the transfer belt from adhering to the secondary transfer roller.

Figure 4-21.

Step 5: secondary transfer

Step 7: separation

The elasticity of the print media causes it to separate from the transfer belt. A static charge eliminator aids separation by weakening any electrostatic adhesion.

Figure 4-22.

Step 6: separation

Fusing stage

The heat of the fuser bonds the toner to the media.

Step 8: fusing

The dc negative bias applied to the fusing film strengthens the holding force of the toner on the print media and prevents the toner from scattering.

Figure 4-23.

Step 7: fusing
Step 9: roller charging (auxiliary transfer belt cleaning roller)
During secondary transfer, not all of the toner on the transfer belt is transferred to the print media. Toner that remains on the belt is called "residual toner." The auxiliary transfer belt cleaning roller, to which a dc positive bias is applied, imparts a positive charge to the residual toner, strengthening its hold on the transfer belt. This prevents toner from falling off of the transfer belt and scattering in the printer.

Figure 4-24.

Step 8: roller charging (auxiliary transfer belt cleaning roller)
Step 10: roller charging (transfer-belt cleaning roller)
The transfer-belt cleaning roller, to which a dc positive bias is applied, imparts a positive charge to the residual toner on the transfer belt. This positive charge is stronger than the positive charge applied in step 8, so the earlier charge now behaves like a negative charge.

Figure 4-25.

Step 9: roller charging (transfer belt cleaning roller)
Step 11: transfer belt cleaning
A dc positive bias is applied to the transfer belt to produce a difference in potential between the belt and the photosensitive drum. This causes residual toner to transfer to the drum.

Figure 4-26.

Step 10: transfer belt cleaning

Step 12: drum cleaning

The cleaning blade scrapes the residual toner off of the photosensitive drum, where the waste toner screws collect the toner and deposit it into the waste toner case.

Figure 4-27.

Step 11: drum cleaning

Print cartridge

The printer has four print cartridges: yellow, magenta, cyan, and black. Each print cartridge contains a developing cylinder, toner-feed roller, and stirrer. The developer motor rotates these parts so that each print cartridge can use toner to form a visible image on the drum. The carousel motor rotates the E-label reader, which communicates E-label information to the dc controller.

The developing rotary/toner level detection PCB uses an LED (light emitter) and a photodiode (light receiver) to determine the toner level in each print cartridge.

Figure 4-28.

Imaging-drum E-label
The E-label is nonvolatile memory, which is built into the imaging drum and stores usage information. When the imaging drum is installed in the printer, the E-label makes constant contact with the E-label reader. The E-label reader sends memory information to the dc controller, which updates the information and sends it back to the E-label. The dc controller instructs the E-label to read information when: The printer is turned on. The top cover is closed. A command is sent from the video controller. The dc controller instructs the E-label to write information when: A specified period occurs during printing. A command is sent from the video controller.
If the E-label reader fails to read or write information four times in a row, the dc controller notifies the video controller that an abnormality exists in the imaging drum.

Figure 4-29.

Print-cartridge E-label