HP LaserJet 2550N print-cartridge carousel rotation

[tensigeka]

Hello:

I have a HP LaserJet 2550N that has been sitting in climate controlled storage for several years. It was working fine, I think it was just low on toner.

Unfortunately the toner cartridges were not pulled out when it was last moved. At this point I can't even get it to print a config page to see drum life, etc.

The print-cartridge carousel indexes properly to all 4 positions with no toner cartridges, but as soon as you start loading them up, after about 2 it doesn't seem to want to index properly. When they are all in, it seems to index properly. However you can rotate the drum by hand (I did carefully and cautiously, I know you are not supposed to), which leads me to believe this is the issue.

After I get them all in, it acts like the Black one is missing and/or sometimes others as well (I think it is slipping when trying to rotate). The contacts on the all the cartridges are clean, and the mating contacts for those are also clean.

Anyone have any experience with this issue?

Is it even worth trying to fix at this point? Usually these older HP's are pretty hearty, and usually only minor issues to fix.

I just downloaded the service manual and am looking over the parts diagrams. I'm reasonably comfortable with taking things apart and putting them back together, if it is something somewhat simple. Just not sure if it is going to be worth the time, but I hate to throw it away if it is fixable.

Thank you for any possible help!

[Valsimot]

It's probably a sticky solenoid in carouser drive, or the solenoid shaft isn't catching the gear and slips.

https://h30434.www3.hp.com/psg/attachments/psg/Printer-Ink-Cartridges-and-Print-Quality/42870/1/2500...