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Lately, I’ve been receiving more calls on the HP small upright color lasers due to poor print quality. I have found that, with most of these lower end HP printer models, the customer doesn’t want to put a lot of money into repairs.

In this article I will focus mainly on the HP 2600 and 2605 because HP doesn’t explain how to remove the laser/scanner in the service manual. In other models, like the HP 2700 and HP 3000 series printers, while they explain in the service manual how to remove the laser/scanner, they don’t tell you how to clean it out once it’s removed.  So I will explain what to look for and how to go about cleaning this so you don’t have to replace it. 

The Problem of Faded Color
The complaints that I’ve been receiving are:

• one color fading, mainly magenta or yellow,
• faded print on the sides through all colors, or
• colors not appearing as the customer believes they should

What To Do About Faded Color
The first thing to do is print a configuration page from the control panel. The configuration page will print several different colors along the side and solid color lines horizontally across the bottom of the page of each individual toner color. You’ll see which colors or areas are actually showing the issue.

Another option is to use a small piece of plastic, like a canned air straw, to press the engine test button through a hole in the middle of the back metal plate. The engine test will print a full page of horizontal lines using each toner. 

Another good option, besides the configuration page for diagnosing the faded color issue, is that you can interchange the toner cartridges in the different slots in the machine. For example, switch the magenta and cyan cartridges and print a config page to determine if the defect follows the cartridge or stays with the slot. This will allow you to determine if there is a cartridge issue (stays with the color), or the laser/scanner or a high voltage contact problem where the different color now has an issue.

Keep in mind that if you put the toners in the wrong slot, the printer will give you a supply error. You cannot print a config page with the error on the display but if you already have a config page requested from the control panel you can open and shut the toner door and it will print the page before the error shows back up on the display.

If the defect stays with the same color then change the cartridge.  If the defect moves to another color then most likely the printer has dirty optics in the laser/scanner.

But, before you go crazy and start tearing the whole machine apart, there are a few more things to look at. First, in the print quality menu, do a color calibration. Color calibration in HP printers can really become off over a period of time. If the colors look off on pictures but the config page prints look good, then you’ve saved yourself a lot of unneeded disassembly.

NOTE:  Unless you are an experienced technician, it is not a good idea to proceed from here. Call an experienced technician in who can safely get your printer back to printing properly.

If you are a seasoned repair technician, then another thing to try, if you determined that the color isn’t printing correctly through an individual slot, is to clean out the exposed lens. To do that, remove the cartridges that are giving you problems, turn the machine off and unplug it. Behind where the two toners sat you will see two horizontal slots in the metal frame with rounded glass pieces in them.

Either gently blow the glass piece out or gently wipe it off with a Q-tip. These glass pieces are extremely sensitive so do not use any force as you could permanently scratch the glass which would require replacement of the whole laser/scanner unit.

When you’re finished cleaning the glass piece plug the printer in and print another config page to see if the problem is gone. If not then you’ll need to disassemble the printer and clean out the laser/scanner optics.

Disassembly of the HP 2600 and 2605 Color Lasers
Note: Steps 5 and 6 are to remove the top cover. I remove it because I believe it allows more room to work and get the side covers back on but it is not necessary.

1. Remove the two screws on the right side; one below the interface connectors and one in the middle of the white plastic piece.
2. Remove the one screw in the middle of the white plastic on the left side.
3. Open the front door, release the tab in the middle of the inside right side, twist the edges of the right side cover, pull out and down to remove. 
4. On the left side below the front door release the white tab, twist the edges of the left cover and pull out and down to remove.
5. Release the control panel cable on the right side in the middle of the frame.
6. On some models the top lifts up and exposes the four screws in each corner that need to be removed. On other models there are two release tabs on the back of the upper face cover between the white plastic and colored cover that need to be released before the cover can be removed. Arrows on the back cover should point you to the correct spot. Once the screws are out the top lid just pulls up and out of the way as long as you have disconnected the control panel cable.
7. Remove the nine screws on the metal back plate. Pull the bottom out and up and away as its hinged on top.
8. None of the boards need to be removed but all the cables need to be disconnected from the back two boards and need taken out of the black plastic wire guides, except for the cables going between the two.
9. Remove the three black wire guides at the top to expose the screws in the metal frame.
10. Remove the 10 screws around the edges of the metal frame and the one in the middle above the formatter and pull up and out from the bottom.
11. Remove the paper tray and cartridges and remove the two leaf metal pieces in the middle of the metal bottom plate above where the paper tray was. You might have to gently put the machine on its right side to see this area or do it before you start disassembly. Once these two metal leaf plates are removed it exposes the screws for the bottom of the laser/scanner assembly. Usually there is only one screw holding the bottom of the unit in place and the other is basically just sitting there like there should be one.
12. Sit the machine back upright. Release the laser/scanner cables from the clip on the right.
13. Remove the two screws on top of the unit and pull it out.

Laser/Scanner Cleaning
Now that you have the laser/scanner out, lay it face up with the four lenses showing and remove the black screw in the middle of the top cover.Release the spring on the shutter actuator arm and pull the top lid off. Once you remove the lid note the placement of the shutter arm for reassembly and then remove it.

You should now see (1) two scanner motors with square metal pieces on top with mirrors on each side (2) four more magenta tinted mirrors at angles and (3) eight round shaped lenses; four small and four large ones sitting on top. Again, these parts are extremely sensitive especially the square scanner mirrors and top lens so use very little force when wiping off and always use a clean Q-tip for each component.

You will probably notice that the two tinted glass pieces that would be sitting on the bottom if held upright are covered in a thin layer of dust. This is because gravity causes the dust to settle more on these mirrors. These are your magenta and yellow mirrors. This is why most service calls are generated for these colors being faded. Clean all four tinted mirrors using a dry Q-tip. Next get yourself at a good angle with the scanner mirrors and gently wipe them off with a clean dry Q-tip.

You probably will notice on one side of the mirrors there is a thin layer of dust. The mirrors move in a certain direction and like a ceiling fan one side gets more of a build-up. This is what creates faded print on the sides of pages through all the colors.

If you notice any scratches starting to appear stop immediately and either get a new Q-tip or, if you think the mirror is clean enough, stop and move onto the next mirror. Clean the four bottom lenses front and back and then move onto the top lenses and repeat. Again, if you see any dirt build up on your Q-tip after cleaning a component, get a new Q-tip before you move onto the next section.

After you have completed cleaning everything go back over it. Tilt the assembly at different angles and check the lenses and mirrors for anything you have missed. Take the time now to do it right. Nothing is worse than reassembling the machine and then figuring out that you forgot to clean off one of the sides of a mirror or lens.

Next gently blow out the assembly and recheck again the mirrors and lenses. Once you are satisfied with the cleaning, note the lenses next to where the shutter arm sits. Wipe these off and reinstall the shutter arm. Put the top cover on, install the screw, reseat the spring, test that the shutter arm moves freely and put the machine back together. Yeah that’s right. I said it so easily.

Pay close attention when you were disassembling the printer! The last thing you want to think about now is “where do all these cables go?” or “I wonder how many screws I’ll have left over?” Good luck, and remember, the thing that helps here is organization.

Test the Machine
Run a few test prints. If your work was done correctly you will notice a huge improvement over the previous test prints. If the lenses were really dirty before you cleaned the machine you will probably notice that your colors are out of alignment so you should perform another color calibration from the print quality menu. Even if you don’t notice an alignment problem you should perform this color calibration anyway. Then clean the printer’s cover, clean the cavity of the machine, and remove the magenta and cyan cartridges so you can remove the metal plate above the pick up roller and clean the roller.

When you are satisfied with your repair, show your customer a copy of a test page before the repair and after the repair. The difference will be night and day.

Conclusion
While putting a maintenance kit in an HP 4250 printer is a nice, profitable service call there is a lot less satisfaction in doing something just about anybody can do. These more obscure problems are my favorite types of repairs. I get to disassemble a lot of the machine. If the customer walks by they usually make a comment like “I could never do that” or “I hope you can remember where all those parts go.” When I get it put back together and they can’t believe the difference in print quality it makes me feel like I am really doing something only a select type of person can do.

Summary
This post covered the repair on the HP 2600 series. The HP 2700 and HP 3000 series uprights have the disassembly instructions in the service manual and the laser/scanner units are fairly similar in design so, once you have the units out, the cleaning should be about the same. HP doesn’t recommend cleaning these components due to their sensitivity but, if you are experienced and if done correctly it will save your customer unwanted cost in servicing their equipment. I know not every service company will perform these repairs; they will simply want to replace the part so offering this service could set you apart from your competition.

I believe with the design of the bottom mirrors, which makes dust have a tendency to sit on them, we will be receiving more of these service calls in the next few years. Hopefully this post will help you properly diagnose and resolve these issues.

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Kevin Gumpp is a certified printer technician and freelance writer for Market Point. If you have a question for Kevin regarding this topic or have any other printer repair related questions or topics you would like more information on, please send an email to maryp@marketpoint.com.