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
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* 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.

Delivery delay jam. The registration clutch is on, and the fuser-delivery sensor (PS1) does not detect the leading edge of the media within 2.3 seconds after the start of a repickup operation. Delivery stationary jam. The leading edge of media does not pass the fuser-delivery sensor (PS1) within 2.4 seconds after it has passed the registration sensor (PS711). Door-open jam. The main CPU detects that the top cover is open during a print operation. Residual jam. The main CPU detects one or more of the following conditions: Power is turned on. The printer door is closed after a jam occurrence. The registration sensor (PS711) and fusing-delivery sensor (PS1) detect media. Paper pickup failure. The sensor (PS717) near the feed roller does not detect media moving through the printer.
Photosensors and switches

Figure 4-8.

Photosensors and switches (1 of 2)

Figure 4-9.

Photosensors and switches (2 of 2)
Table 4-3. Photosensors and switches
Reference 7 Description Tray 1 sensor Roller-engaging sensor Developing-rotary-engaging sensor Fuser-delivery sensor Front fuser-detection sensor Door-open detection switch Power switch

Solenoid and clutches

Figure 4-10.

Solenoid

Table 4-4. Solenoid
Reference Description Developing-rotary-stopper solenoid Tray 1 pickup solenoid

Figure 4-11.

Clutches

Table 4-5. Clutches

Reference Description Roller-engaging clutch Registration clutch
Printed circuit assemblies

Figure 4-12.

Printed circuit assemblies (1 of 2)

Figure 4-13.

Printed circuit assemblies (2 of 2)
Table 4-6. Printed circuit assemblies
Reference 9 Description Developing-rotary/toner-level detection PCA Transfer-belt home-position detection PCA Waste-toner-detection PCA Density-detection PCA Registration-detection PCA Dc controller Sub high-voltage power-supply PCA High-voltage power-supply PCA Power supply

Image-formation system

The image-formation system, which forms a toner image on media, consists of several interdependent systems: Electrostatic latent-image-formation system Developing system Transfer block Fuser Transfer belt cleaning block Imaging drum (with ITB) Photosensitive drum

Figure 4-14.

Image-formation process
Laser printing requires the interaction of several different technologies including electronics, optics, and electrophotographics to produce a printed page. Each process functions independently and must be coordinated with the other printer processes. Image formation consists of the following five processes: 1. Latent-image formation 2. Developing 3. Image transfer 4. Fusing 5. Transfer-belt cleaning The five processes are divided into twelve steps, which are shown in the Image-formation process graphic and are described in the following sections.

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

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

4 Managing the printer

The HP color LaserJet 2550n printer has the same features as the HP color LaserJet 2550Ln printer and also includes tray 2. This model also accepts optional tray 3. This model comes standard with high-capacity color print cartridges that can print up to 4,000 pages.

Printer features

Feature Color printing HP color LaserJet 2550 series printer Provides laser printing in full color by using the four process colors: cyan, magenta, yellow, and black (CMYK). Prints in black on letter-size paper up to 20 ppm and on A4-size paper up to 19 ppm. Prints in color on A4/letter at 4 ppm. ImageREt 2400 provides 2400 dpi color and laser-class quality through a multilevel printing process. True 600 by 600 dots per inch (dpi) text and graphics. Adjustable settings to optimize print quality. The HP UltraPrecise print cartridge has a finer toner formulation that provides sharper text and graphics. Few supplies to order. Supplies are easy to install. Convenient access to printer information and settings by using the HP Toolbox software. Convenient access to all supplies and to the paper path through the front door. Optional tray 2. (Included with the 2550n model; compatible with all other models.) This 250-sheet tray for standard sizes reduces how often you have to add paper to the printer. Only one 250-sheet tray can be installed on the printer. Optional tray 3. This 500-sheet tray for letter and A4 sizes reduces how often you have to add paper to the printer. Only one 500-sheet tray can be installed on the printer. Optional tray 2 must be installed in order to install optional tray 3. Optional HP Jetdirect external print server for connecting to a network (HP color LaserJet 2550L printer). One DIMM slot for adding memory and fonts.

Fast print speed

Excellent print quality

Ease of use

Expandability
Feature Flexible paper handling
HP color LaserJet 2550 series printer Adjustable tray 1 (multipurpose tray) for letterhead, envelopes, labels, transparencies, custom-sized media, postcards, glossy paper, HP LaserJet Tough paper, and heavy paper. Optional tray 2 (250-sheet tray) that is adjustable for several standard sizes of paper. Optional tray 3 (500-sheet tray) for letterand A4-size paper. (Optional tray 2 must be installed in order to install optional tray 3.) One 125-sheet output bin and one output door. Select the top output bin (face down) for most jobs, including transparencies. Use the rear output door (face up) for jobs on heavy paper, light paper, or special print media. Straight-through paper path capability from tray 1 to the rear output door. Manual two-sided printing (duplexing). See Printing on both sides (duplexing manually). Fast printing performance, built-in Intellifont and TrueType scaling technologies, builtin HP-GL/2 vector graphics, and advanced imaging capabilities are benefits of the PCL 6 printer language. The PCL 6 also includes 45 scalable TrueType fonts and one bitmapped Line Printer Font. The PCL 6 printer language also included. Includes 35 built-in PS language fonts. The printer automatically determines and switches to the appropriate printer language (such as PS or PCL 6) for the print job. Bidirectional enhanced capabilities port (ECP) type-B parallel port (IEEE-1284 compliant). High-speed USB port. Accepts an optional HP Jetdirect external print server (HP color LaserJet 2550L printer). The HP color LaserJet 2550Ln and 2550n printers include an HP Jetdirect internal print server.

parallel port (IEEE-1284B) high-speed USB port 10/100Base-T port (HP color LaserJet 2550Ln and 2550n printers only)

Software

Software and supported operating systems
For easy printer setup and access to the full range of printer features, HP strongly recommends that you install the software that is provided. Not all software is available in all languages. See the getting started guide for installation instructions, and see the Readme file for the latest software information. The most recent drivers, additional drivers, and other software are available from the Internet and other sources. If you do not have access to the Internet, see HP customer care. The printer supports the following operating systems: Microsoft Windows 98, Windows 2000, Windows Millennium Edition (Me), and Windows XP Windows NT 4.0 (driver only, other printer software is not available) Macintosh OS 9.1 and OS X v.10.1 and later UNIX, Linux, and OS/2 (limited functionality)
The following tables list the software that is available for your operating system. HP color LaserJet 2550 series printer software
Feature Windows 98, Me Windows 2000 and XP Macintosh OS 9.1 Macintosh OS X UNIX, Linux OS/2
Windows Installer PCL 6 printer driver PS printer driver HP Web Jetadmin software HP Toolbox software Macintosh Installer Macintosh PostScript printer description (PPD) and printer dialog extensions (PDE)
HP color LaserJet 2550 series printer software (continued)
IBM drivers Model scripts
Available on the HP website. Available on the HP website. Not specific to this printer.

Software tips

The following are some tips for working with the printer software.
How do I gain access to the printer features?
The printer features are available in the printer driver. Some features such as custom paper sizes and page orientation might also be available in the program you are using to create a file. Change settings in the program, if possible, because changes that are made in the program override changes that are made in the printer driver. Gain access to advanced printer features through the printer driver (or the Print dialog box for Macintosh operating systems). See Gaining access to printer driver settings for help with specific printer-driver features.
How do I get the latest printing software?
When you want to check for and install upgrades to the printing software, you can download drivers from the World Wide Web or HPs file transfer protocol (FTP) servers. To download drivers 1. Go to http://www.hp.com. Click the support & drivers block. 2. Type color laserjet 2550 as the product name. The Web page for the drivers might be in English, but you can download the drivers themselves in several languages. If you do not have Internet access, contact HP Customer Care. (See HP customer care or the flyer that came in the printer box.) See the Readme file for additional release information.

hp color LaserJet

Supplies Status Page

2550 series

1. Print-cartridge area. This area contains a section for each of the print cartridges and provides information about HP print cartridges. This information includes the part number for each print cartridge, whether each print cartridge is low, and the life remaining for each print cartridge expressed as a percentage, as a graphic, and as the estimated number of pages remaining. This information might not be provided for nonHP supplies. In some cases, if a non-HP supply is installed, you see an alert message instead. 2. Imaging-drum area. This area contains the same information for the imaging drum that the print-cartridge area provides for the print cartridges.
3. Warranty Note. This section contains information about how the printer warranty is affected when you use non-HP supplies. It also requests that you call the HP fraud hotline if a supply that is being detected as a non-HP supply was sold to you as a genuine HP supply. (See HP fraud hotline.) 4. Ordering Information. This section contains basic information about how to order new HP supplies. 5. Recycling Information. This section contains a link to the website that you can visit for information about recycling.
The HP Toolbox is a Web application that you can use for the following tasks: Check the printer status. Configure the printer settings. View troubleshooting information. View online documentation.
You can view the HP Toolbox when the printer is directly connected to your computer or when it is connected to the network. You must perform a complete software installation to use the HP Toolbox. Note You do not have to have Internet access to open and use the HP Toolbox. However, if you click a link in the Other Links area, you must have Internet access to go to the site that is associated with the link. See Other links for more information.
Supported operating systems
The HP Toolbox is supported for the following operating systems: Windows 98, 2000, Me, and XP Mac OS X, v. 10.1 or later

Supported browsers

To use the HP Toolbox, you must have one of the following browsers:

Windows

Microsoft Internet Explorer 5.5 or later Netscape Navigator 6.2 or later Opera Software ASA Opera 7 or later

Macintosh (OS X only)

Microsoft Internet Explorer 5.1 or later Netscape Navigator 6.23 or latere Safari 1.0
All pages can be printed from the browser.

To view the HP Toolbox

1. Open the HP Toolbox in one of these ways: Note On the Windows desktop, double-click the HP Toolbox icon. On the Windows Start menu, point to Programs, and click the HP Toolbox. For Macintosh OS X, on the hard drive, click Applications, and then click the Utilitites folder. Double-click the HP Toolbox icon.

HP fraud hotline

Call the HP fraud hotline if the supplies status lights or HP Toolbox indicates that the print cartridge or imaging drum is not an HP print cartridge and you think that it is genuine. HP 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 one 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 it usually does (for example, the pull tab or the box is different).
In the United States, call toll-free: (1) (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: (1) (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 will translate between you and the representative for the HP fraud hotline.

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. This printer has a cleaning mode that can correct and prevent these types of problems.

To clean the engine

Note The following procedure must be performed from the HP Toolbox. To clean the engine when the computer is running an operating system that does not support HP Toolbox, see the latebreaking Readme on the root of the CD-ROM, or visit http://www.hp.com/support/clj2550. 1. Make sure that the printer is turned on and in the Ready state. 2. Open the HP 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.
6. At the computer, press Clean.

Calibrating the printer

The printer automatically calibrates at various times. You can adjust the calibration settings by using the HP 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 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.

The printer does not recognize the tray. The separation pad and the pickup rollers might be worn.
Turn the printer off then on. Replace the separation pad and pickup rollers. Contact HP Customer Care to order parts. See HP customer care or see the support flyer that shipped in the printer box.
The printer does not recognize a DIMM that is installed. Cause The DIMM is not recognized in the printer driver. The DIMM is not properly installed. Solution Set the printer driver to recognize the DIMM. See Enabling memory. Remove the DIMM, and reinstall it.
The printer does not respond when the Print command is selected in the software. Cause The printer experienced an error. If no control panel lights are on, the printer is not receiving power. Solution Check the control panel lights on the printer to determine if an error exists. Check the power cable connection between the printer and the power source. Check that the power switch is on. Check that the power source (outlet or surge protector) is receiving power. If none of the above measures works, contact HP Customer Care. See HP customer care or see the support flyer that shipped in the printer box.
The printer might be in Manual Feed mode (Attention light blinking and Go light on). The wrong printer was selected in the software. A jam might exist. The printer is on a network and is not receiving a signal.
Add paper to tray 1 if it is empty. If paper is already in the tray, press (GO).
In the Print or Printer Setup dialog box, make sure that the HP color LaserJet 2550 printer is selected. Clear any jams. See Clearing jams. Disconnect the printer from the network and attach it directly to a computer by using a parallel or USB cable. Clear any stopped jobs from the print queue. Print a job that you know works. Reinstall the printing software.
The interface cable between the computer (or network) and the printer is not connected properly. The interface cable is defective.
Disconnect and reconnect the interface cable. If possible, connect the interface cable to another computer (or network port) and print a job that you know works. Try using a different cable.
If the printer is connected to a computer, the software for the printer is not configured for the printer port.
Check the printer selection menu in the software to make sure that it is using the correct port. If the computer has more than one port, make sure that the printer is associated with the correct one.
Pages print, but not all of the colors print, or the pages are completely blank. Cause If one color is completely missing, the sealing tape might not have been removed completely from the print cartridge. If pages print completely blank, the file might have blank pages. If you are using non-HP print cartridges, one or more print cartridges is low or empty. The control panel lights do not indicate low or empty status for non-HP print cartridges. The Font DIMM check box might be selected but the font DIMM is not physically installed in the printer. (This issue only applies to printers that are using an Asian-language font DIMM.) Solution Remove the print cartridge for the missing color and make sure all the sealing tape has been removed completely. Check the file to see if it contains blank pages. Delete those pages if they are unnecessary. Replace one or more of the print cartridges.

In the settings for this printer, click to clear the Font DIMM check box on the Configure tab if no font DIMM is installed in the printer. Select the Font DIMM check box only if the font DIMM is physically installed in the printer. If you think that the font DIMM is installed, make sure that it is installed correctly.
The media curls when exiting the top output bin. Cause The media needs to print to the straight-through paper path. The stack was slightly curled when it was placed in the tray. The print media does not meet specifications. If you are printing on light media, the Type setting might not be correct. Solution Open the rear output door to print to the straight-through paper path. Remove each sheet as it exits the printer. Turn the stack over in the tray. See Print-media specifications. Select Light in the Type is field in the printer driver.
The printer prints, but the text is wrong, garbled, or incomplete. Cause The interface cable is loose or defective. Solution Disconnect the printer cable and reconnect it. Try a print job that you know works. If possible, attach the cable and printer to another computer and try a print job that you know works. Finally, try a new cable. Disconnect the printer from the network and attach it directly to a computer by using a parallel or USB cable. Print a job that you know works. In the Print or Printer Setup dialog box, make sure that the HP color LaserJet 2550 printer is selected. Print a page from the HP Toolbox. If the page prints, then the problem is with the printer driver. Uninstall and reinstall the printer driver. Try printing a job from another program.
The printer is on a network or sharing device and is not receiving a clear signal. The wrong driver was selected in the software. The printer driver is malfunctioning.
The program is malfunctioning.
The printer prints, but the text is wrong, garbled, or incomplete. Cause If the printer is connected to a computer, the operating system is malfunctioning. Solution Check the operating system. If you do not know how to use the following method, see the documentation that came with the computer. Restart the computer. When it beeps during startup, press F5 and select Command Prompt Only. At the C:\ prompt on the computer, type Dir>LPT1 and then press Enter. (This assumes the printer is connected to LPT1.) If the Go light comes on at the printer, press (GO) to print and eject the page. If the page prints correctly, then the operating system is malfunctioning. The font DIMM check box might be selected but the font DIMM might not be physically installed in the printer. (This issue only applies to printers with an Asian-language font DIMM installed.) If the font DIMM is not installed in the printer, open the printer driver and on the Configure tab, and click to clear the Font DIMM check box. If a font DIMM is installed, the check box should be selected, but make sure that the actual font DIMM is installed correctly in the printer.

The wrong connection type might be selected.
The wrong printer name or IP address is being used.
The PostScript Printer Description (PPD) file for the printer does not appear as a selection in the Desktop Printer Utility Cause The printer software might not have been installed or was installed incorrectly. Solution Make sure that the HP color LaserJet 2550 PPD is in the following hard drive folder: System folder/Extensions/ Printer Descriptions. If necessary, reinstall the software. See the getting started guide for instructions. Delete the PPD file from the following hard drive folder: System Folder/Extensions/Printer Descriptions. Reinstall the software. See the getting started guide for instructions.
The Postscript Printer Description (PPD) file is corrupt.
Problems with Mac OS 9.x. (continued)
A print job was not sent to the printer that you wanted. Cause The print queue might be stopped. The wrong printer name or IP address is being used. Another printer with the same or similar name or IP address might have received your print job. Solution Restart the print queue. Open the Printing menu in the top menu bar and click Start Print Queue. Check the printer name or IP address by printing a (GO) and (CANCEL configuration page. (Briefly press JOB) simultaneously.) Verify that the printer name or IP address on the configuration page matches the printer name or IP address in the Desktop Printer Utility. Make sure the cables are connected correctly, the printer is on, and the ready light is on. If connecting through a USB or Ethernet hub, try connecting directly to the computer or use a different port. Replace the interface cable. Make sure to use a high-quality cable.
The printer might not be ready.
The interface cable might be defective or of poor quality.
You cannot use the computer while the printer is printing. Cause Background Printing has not been selected. Solution For LaserWriter 8.6 and later: Turn Background Printing on by selecting Print Desktop on the File menu and then clicking Background Printing.
An encapsulated PostScript (EPS) file does not print with the correct fonts. Cause This problem occurs with some programs. Solution Try downloading the fonts that are contained in the EPS file to the printer before printing. Send the file in ASCII format instead of binary encoding.
Your document is not printing with New York, Geneva, or Monaco fonts. Cause The printer might be substituting fonts. Solution Click Options in the Page Setup dialog box to clear substituted fonts.
You are unable to print from a third-party USB card. Cause This error occurs when the software for USB printers is not installed. Solution When adding a third-party USB card, you might need the Apple USB Adapter Card Support software. The most current version of this software is available from the Apple website.

Resolving problems that generated messages
This section helps resolve problems that generated messages on the computer.
Messages for both Windows and Macintosh
This section lists some common errors that provide only a simple message but no information for resolving the error. Errors that you see in HP Toolbox provide their own instructions for resolving the error. For other errors that are generated by your operating system, see the documentation for the operating system or computer.
Limit Check Error Cause The print job is too complex. Solution You might need to reduce the complexity of the page or install more memory. Use one of the other printer drivers. Send the print job in smaller pieces or in fewer pages.
Messages for Windows only
Message "Error writing to LPTx" in Windows 98 or Me Solution Make sure that the tray contains print media. Make sure that the cables are connected correctly, the printer is on, and the Ready light is on. Print a Demo page from the HP Toolbox to make sure that the computer can communicate with the printer. On the Start menu, point to Settings and click Printers. Right-click the HP color LaserJet 2550 driver and select Properties. Click Details and then click Port Settings. Clear the Check Port State before Printing check box and click OK. Click Spool Settings, select Print Directly to Printer, and click OK. Try printing again.
Message "General Protection Fault" "Exception OE" "Spool32" "Illegal Operation"
Solution Restart the computer and try again. Clear the contents of the computer Temp folder, which is generally located in C:\Windows (for Windows 98 and Me) or C:\Winnt (for Windows 2000 and XP). Change the graphics mode in the driver from raster to vector, or from vector to raster.

Other Windows messages

For more information, see the Microsoft Windows 98, 2000, Me, or XP documentation that came with the operating system or computer.
Resolving the control panel messages
Printer status is indicated by light patterns on the control panel. Two sets of lights are on the control panel: Supplies Status lights and Printer Status lights:
The lights can be in any one of the following states:

off on blinking

See the following information to interpret control panel lights. See the HP Toolbox to view animations of the light patterns and information about the messages that they indicate.

Supplies Status lights

This section describes the meaning of the patterns for the lights in the Supplies Status area. Information about supplies also appears in the HP Toolbox. (For more information, see Maintenance.) To order new supplies, see Accessories and ordering information.

Repetitive defects on the back

Misformed characters

Curl or wave
Page skew Random image repetition (dark)

Wrinkles or creases

Toner scatter outline
Random image repetition (light)

Light print or fade

A vertical streak or an incorrect or faded color area appears on the page.
The print media might not meet HP specifications (for example, the paper is too moist or too rough). See Print-media specifications. One or more print cartridges are low. If you are using non-HP print cartridges, no messages appear on the printer control panel or in the HP Toolbox. The imaging drum might be low or empty. Print the Supplies Status page to check the remaining life. Replace the imaging drum if it is low or empty. If none of the print cartridges or the imaging drum is low or empty, remove the print cartridges one at a time and inspect the toner roller in each to see if the roller is damaged. If so, replace the print cartridge. If the light printing is on the left side of the page, the carousel might be dislocated. Service is required. If the problem is not resolved, see If the problem is not resolved.

Toner specks

Specks of toner occur randomly on the page. The print media might not meet HP specifications. For example, the paper is too moist or too rough. See Print-media specifications.
The paper path might need cleaning. See Cleaning the printer. If the problem is not resolved, see If the problem is not resolved.
Faded areas, generally rounded, occur randomly on the page.
A single sheet of print media might be defective. Try reprinting the job. The moisture content of the paper is uneven or the paper has moist spots on its surface. Try different paper, such as high-quality paper intended for laser printers. See Printmedia specifications. The paper lot is flawed. The manufacturing processes can cause some areas to reject toner. Try a different brand of paper, such as high-quality paper intended for laser printers. See Print-media specifications. The imaging drum might be defective. See Repetitive defects on the front. If these steps do not correct the problem, 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.
Vertical streaks or bands appear on the page.
One or more print cartridges are low or defective. Print the Supplies Status page to check the remaining life. If you are using non-HP print cartridges, no messages appear on the printer control panel or in the HP Toolbox. Clean the printer by using a cleaning page. See Cleaning the printer. Use the tools on the Troubleshooting tab of the HP Toolbox to correct the problem. If the problem is not resolved, see If the problem is not resolved.

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

trays features 7 included 4 jams, clearing 100 loading 28 locating 9 media supported 21 part numbers 123 selecting 33, 37 troubleshooting 78 troubleshooting accessory errors 98 blank pages 80 calibrating printer 72 checklist 74 color 114 Configuration page, printing 52 consumables status messages 92 control panel messages 91 curl 80, 112 Demo page, printing 52 EPS files 84 faded print 107 fonts 82, 84 jams 99 Limit Check errors 89 lines 108 Macintosh problems 83 media 104 PostScript (PS) errors 82 print-quality problems 105 printer status messages 95 printing 79 repetitive defects 110, 114 replacing print cartridges 69 secondary printer status messages 98 skewed pages 112 slow printing 77 text 80 toner smear 107 trays 78 wrinkles 113 Troubleshooting tab, HP Toolbox 56 TrueType fonts, included 7, 119 See also fonts two-sided printing 48 typefaces. See fonts types, media selecting trays by 33, 37 U uninstalling software 14 UNIX support 11 upgrading memory 148 USB cables, ordering 122
USB port connecting to 9 locating 9 troubleshooting 84 type included 7 user guide accessing 58 part numbers 127 user replaceable parts 126 V vertical lines, troubleshooting 108 voltage requirements 138 W warranty extended 132, 143 print cartridge 131 product 129 watermarks 38 wave, troubleshooting 80, 112 Web browser requirements 55 Web Jetadmin operating systems supported 11 toner level, checking from 69 using 13
websites customer support iii HP Printing Supplies Returns and Recycling Program 142 HP Web Jetadmin 13 Material Safety Data Sheet 143 weight printer 137 Windows driver features 36 driver Help 36 printing from 34 settings 35 uninstalling software 14 versions supported 11 wrinkles, troubleshooting 113 Y Yellow cartridge empty or missing, light messages life expectancy 68 low 92 non-HP 95 part number 120 status light 24, 92 See also cartridges
2004 Hewlett-Packard Development Company, LP
www.hp.com/support/clj2550
*Q3702-90952* *Q3702-90952*

Q3702-90952