HP 2550L won't print in anything but yellow unless I change it to grayscale.

[GailBass]

HP 2550L - replaced 3 of the four cartridges. Printer will print but only anything that is yellow. Will print in black if it is just a black/white document or grayscale is selected. Drum was also replaced. I've tried re-booting - putting the old cartridges back in but they indicate that they need changing. Question - would 1 cartridge make a difference? They are all authentic HP cartridges. Before I bring this to a service center, I would really like to know if it is worth putting more money into it. Thank you for any help that you may be able to provide me.

[SHThompson]

There is a known issue with the Carousel Latch, (Brake), it is part of the Rotary Drive Assembly.

Search on: hp 2840 carousel solenoid repair

You can also search for: HP 2840 Service Manual

The repair process involves:

Rremoving the assembly the solenoid is mounted on

Rremoving the solenoid arm, (arm removal is easy)

Scraping off the gooey residue from the deteriorated foam rubber pad

Replace the pad with a very thin piece, (I use the cheap felt pads found at Dollar Stores), you have to put something in to replace the old pad or the residual magnetism will cause the bare metal pieces to stick together.

If my answer solves your problem please mark it as a solution by clicking the button under the post. 

If any Tech gives you helpful suggestions you can thank them by giving them "Kudos", (just click the "Thumbs Up" button under the post).

If you're in a good mood you can even click both buttons...

[GailBass]

OK, so the carousel solenoid brake is sticking. I found directions for fixing this along with your instructions but it sounds not only complicated but for another machine. I need more detailed explanation of how to replace the felt pad. Where would I find directions that pertain to the HP 2550L? Thank you.

[SHThompson]

Whoops, just put 2550 in your search instead of 2840.

The 2500/2550 engine is the same as is used in the 2840.

Essentially at 2840 is a 2500 with the scanner on top of it.

When you buy the sheet of a very thin felt pads somewhere they have adhesive on one side, you simply stick the thin pad in place of the foam residue. When I say then there probably no thicker than a business card.

The latch is sticking in the unlocked position which lets the carousel drift during printing, since yellow is the first color printed the latch is holding the carousel still for that color and after it is released for the rotation of the next color it does not latch the second color in position.

If you open the top cover when the machine is failing you should be able to move the carousel freely, eventually the solenoid will pop back into its locked position and you'll be able to get another page of yellow.