HP 2840 skipping colors

[RayKremer]

So we have an HP 2840 color laser printer/scanner unit. In the past week or so, it's started giving printouts with one or more colors missing. It's fairly random, sometimes the printout is fine, and when it does skip a color it can be any of the four. When it prints you can hear the unit rotating to each of the four toner carts in turn, and when it skips a color the noise is different. I'm not sure if a gear is jamming or slipping or what.

Has anybody seen this or know what I need to look for?

[davidzuts · Accepted solution]

This is a common issue on this series. What has happened is the solenoid that stops the carousel in the correct position is not working right. You can correct the problem but it will take a bit of work. On that solenoid is a felt pad that was used to dampen the sound of the "L" arm hitting the metal and also to prevent the arm from becoming magnitized. You need to remove the right side cover and the top cover. Suggest you do a google search for the service manual. I have attached 2 pages from the manual to show you the location of the solenoid. The first page shows how to lift the "L" arm to move the carousel and the 2nd page shows the cover you need to remove to access the solenoid. You only need to disconnect the wire going to solenoid at the side of the printer and remove the 1 screw that secures the solenoid to the printer frame. You then lift the solenoid so you can access the spring that holds the L arm in place. You remove the spring, remove the L arm and then clean up all the residual glue left over from the pad on the solenoid ledge and the L arm. You have to put some form of replacement material down. I use a very thin furniture pad cut down or you can use part of a velcro pad. When removing the solenoid only pull it far enough up to access what you need leaving the wire on the right side of the printer still outside the housing so it is easy to put back.

[RayKremer]

​Well, that was certainly an adventure, but I managed to get the solenoid out, cleaned off the old foam, put in some new foam, got it all back together, and it still prints.

And I certainly did need the service manual, just to figure out how to get some of the outer panels off, ha! It certainly is an adventure in taking off bits just to have access to the screws that you need to remove to get to the bit that's important.

Thanks!