My HP Color LaserJet 2600N printer recently experienced the infamous faded red tones, this is due to the magenta toner being positioned at the bottom of the unit and the optics being the most susceptible to dust and debris.
Here is the details of repairing the unit based on Don Thompson’s Service Seminars whitepaper found at the end of this post.
The HP LaserJet 2600N printer, first remove all the toner, the paper trays and the output trays. Then remove the screw on the left hand side of the unit near the paper tray.
Unclip the plastic hook and remove the left hand side plastic cover.
Do the same for the screw on the right hand side of the unit near the paper tray.
There is a second screw to remove near the network ports. Then remove the right hand plastic cover.
Remove the nine screws from the back of the unit.
Remove all connectors as circled, all the plugs are different sizes making it easy to reassemble. Care should be taken removing the ribbon cables as they are similar sized. Also remove the black cable trays by sliding them to the left to release the catches.
Remove total eleven screens, those in the photo and those under removed cable trays and ribbon cables.
Lift the PCB plate away revealing the black box of optics. Unscrew the screws holding the black box.
Remove the single screw at the bottom of the printer holding the optics box in place. Remove the optics box.
Once the optics box is removed, unclip the spring to allow access inside.
Using an air blowing brush similar to those used on DSLR cameras, clean all the lens and mirrors.
Reassemble everything in reverse order. Care should be taken making sure the ribbon cables are seated in both ends.
Further details can been found in Don Thompson’s Service Seminars whitepaper.