asked Feb 4, 2017 at 1:19pm
Hp HP Color LaserJet 2840

Color printing issue...

My 2840 has been working great for the past the past 8 years (I purchased it 2nd hand). 80% of what I print is black & white. In the last month color printing is becoming erratic. On a multipage color doc print job page 1 is fine, page 2 is reddy/orange, page 3 is mostly yellow and subsequent pages fade out to nothing. Engine test passes, all supplies are full, supplies status page report is normal, demo page prints normally, print test page from windows XP is normal, printer firmware is up-to-date. Since color is crapping out on multiple page docs I am assuming my carousel is indexed properly (I only use new HP cartridges)...is my machine suffering the the sticking solenoid disease? Or is there something else I need to look at? Thanks in advance for any/all suggestions...

Could be a sticking solenoid issue given the fact that the sticking usually happens when it gets hot after a page or 2. Also, given the age of the printer it is highly likely to have deteriorated. Really hard to access in that printer. I developed a minimalist approach to it. I take off the right side panel and whatever parts are in the way to access a hole to the right of the solenoid. Then using a pocket knife, I scrape off the gooey stuff through the hole and using tweezers I replace it with a sticky backed piece of felt. I call it a surgical repair. My mother wanted me to be a doctor. It saves over an hour of work.

by moe on Feb 4, 2017 at 9:07pm Add comment

Moe: Thx for the quick reply. "Right side panel" is the one on my right as I view the front of the printer? Size & thickness of the felt pad replacement piece? Any photos/videos/diagrams you can share of this area and/or procedure? Or it is obvious once the panel is removed? Do I need to remove any/all toner cartridges and/or drum prior to surgery to make this easier?

by heloflights on Feb 4, 2017 at 9:18pm Add comment

Yes, right side looking from front. This video shows the location of the carousel release solenoid. You want to use thin felt. You can find it at a hardware store. The kind that is for the bottom of chair legs. Here is a service manual to help with disassembly.


by moe on Feb 5, 2017 at 12:31am Add comment

Moe - Thx for the info. Video link wasn't included in your last post...? Is this the one?


by heloflights on Feb 5, 2017 at 10:42am Add comment

Laproscopic Carousel Solenoid Brake procedure completed, success! For those who might face this issue in the future here's my notes:

1. The repair manual is available on the HP web site, look at pages 180-182, 196-198 and 374-375 for reference.

2. I removed all of the toner cartridges, paper tray and drum before I moved the printer to a large work area. I placed a towel on the work surface so I could easily spin the printer around. Not a bad idea to have some small bins for holding removed screws.

3. While all of the supplies were removed it is a good time to use a small vac then lint-free tissues and alcohol and clean up all of the loose toner.

4. I rested the printer on the left side while working on the right side (right side was up).

5. Remove the right side panel. right rear cover, and right rear corner cover. Not a bad idea to snap digital photos as you go so you can remember where thing go back together.

6. Carefully disconnect all of the cables (top & bottom) then remove the 4 screws securing the formatter box and remove it.

7. Use clothespins to keep the cables out of the way.

8. Remove the 2 screws securing the motor and let it dangle. There is a single philips screw securing the "L" bracket, CAREFULLY remove this screw (DON"T DROP IT) this will allow you to fidget the bracket a bit providing more room to work on it. There are 2 alignment pins that will help you place it back into correct position at the end of the procedure.

9. You now have access to the solenoid through a hole adjacent to it. Using a stiff artist spatula, scrape off the old foam bumper pad and glue. Next use stiff q-tips, soaked with CRC QD electronic cleaner and remove all traces of the old adhesive. Rubbing alcohol was not strong enough to remove the old glue. Take you time on this step to be sure the "L" bracket surface is nice and clean.

10. Cut out a replacement self-adhesive felt pad (I used green self adhesive furniture felt from Home Depot), .290" wide x .740" long x ~.050 thick. Peel off the backing and place the new pad on the very tip of an X-acto knife, this tool will allow you to position the pad into position, while holding it there use a small flat tool to press the new pad into place. It is very important to install a new pad, this prevent the bracket from becoming magnetized.

11. Put everything back together, you are done. Being a rookie at this I took my time, the procedure took about an hour.

by heloflights on Feb 5, 2017 at 2:58pm Add comment

Good work. You probably saved over 2 hours removing the top and other stuff to get access to the solenoid. Glad I was able to help you with my laproscopic procedure.

by moe on Feb 6, 2017 at 6:02pm Add comment