How to clean a density sensor unit on a hp color laserjet 8550

Hi Elias, The link below is a user manual for a color laser jet 8500, 8500n, 8500dn, I had a look and the answer to your question (Clean density sensor) is on page 155 (To clean the density sensor
1 Open the upper right door.
2 Use the brush located next to the sensor to remove all toner particles from the sensor)..... This WILL Help...CHEERS..
http://h20566.www2.hp.com/hpsc/doc/public/display?docId=emr_na-c00656644

54.06

Error message

54.06

Description

Color density sensor error

Action

1. Power cycle the printer.
2. Calibrate the printer. Click here to view the document "HP Color LaserJet 2600n - Calibrating the printer" available on the HP Web site at (http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00314525).
3. Change the Print Density settings through the HP Toolbox. Click here to view the document " HP Color LaserJet 2600n Printer - Change Device Print Settings in HP Toolbox" available on the HP Web site at (http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?objectID=c00310627).
4. If the problem continues, contact HP Customer Support Center for technical assistance athttp://www.hp.com/support/clj2600n or see the flyer that came in the printer box for additional contact information.

Hi Harden,
Thats an issue with the fuser assembly,try to check the teflon condition/ teeth gear might have worn out.

have you tried to clean the heads on it?

Try using the HP Print Diagnostic Utility in Windows - HP Customer Care (United States - English)

This could be color miss registry, even though your printer is a monochrome printer there is a sensor which determines the color density, Black being a color, and if the sensor is damaged will cause issues like fading. Make sure you are using hp original cartridges, and if the problem is still there, contact hp for warranty options, hp's tech support line is 1800-334-51440.

Al
[email protected]

The Density Sensor is located inside the right upper door and senses the colour calibration pattern for each colour formed on the transfer drum during a calibration cycle. Press GO. Print a configuration page and then troubleshoot as an Image-quality problem as instructed in the user manual. Check the transfer guide for cracks and replace if necessary. Check the event log for errors numbered 54.00.0<X> the X indicates, 5-sensor abnormality, 4-Cyan, 3-Magenta, 2-Yellow, 1-Black. The last 3 error codes should be seen on the Configuration page.

If the error is '20.00 Insufficient Memory'
No action required. It is simply out of memory because the file you printed was too big.
If you keep getting the message, simpify the print job and/or add more memory to the device.

You could also..
Change the setting in the <Configuration Menu>, <Clearable Warnings>, from 'On', to "Job'.
This will get rid of the message a bit quicker.

Disconnect your network cable and printer's hard drive and then power on. Its possible there is a stuck job somewhere.

If that doesn't work, believe or not it could be the fuser.

CLEAN THE DENSITY SENSORS POINTING AT THE TOP OF THE TRANSFER BELT. A COLD RESET CAN HELP TOO