All too often the toner/drum cartridge will not readily slide out of its socket. The left side releases while the right side remains fixed; this right side carries the driveshaft for the assembly. The driveshaft has 2 metal pins that mate with the main drive motor driveshaft attached to the chassis. Whether the cartridge slides out easily or not depends on how these pins are oriented when the motor stops; that's random. I can not tell if the motor has a clutch to disengage the 2 halves of the driveshaft that might cause this.

If the cartridge is stuck, it is necessary to power cycle on/off printing test pages until the mechanism is freed. Often many times.

Is anyone familiar with this? Or has a suggestion for repair? Could the cartridge be at fault? All printing is otherwise fine.

I've done a fair number of Electromechanical/Eolectronic repairs over the years on my kit and everyone else's. My bet would be on toner powder on something sliding or revolving, and gumming up the works. I'd try a solvent perhaps fdollowed by a light oil?

toner powder where? (inside the sealed cartridge) solvent on what? oil what?

When the front door is opened, is the cartridge driveshaft disengaged from the main drive motor? I can not tell visually when the cavity is open.

You'd be amazed how dirt gets around. It doesn't hurt to try it, no harm done if my advice achieves nothing. It rules out a few options.

Btw, I offered advice - only that. Your prpblem sounds like moving parts sticking. I'm suggesting solvent on the moving parts. I haven't a clue what your printer looks like and you certainly haven't helped there. We use the information you provide to help you, which in this case was nearly nil.

Not so. Original posting title: HPLJ M402dn!

Yes, it did. I tried to offer helpful advice. But I'm not going to do research or look things up in order to do that.

True, but no photos or fully detailed descriptions. For anyone else to know exactly what you are seeing they either have to have the same printer or a (hopefully) detailed enough service manual with photos of the area and components described to analyze the problem.

Most service manuals I have found are not that detailed, especially when related to home printers. Service is usually more expensive than replacement.

Only with hands on can one of us fully evaluate the issue and the suggestion by business_kid is fully valid and expects you to investigate further into the issue.

I would, however, not suggest using oil but rather a dry lubricant such as lock-ease to avoid attracting and trapping dust/lint/powder in that area.

Are you using an HP toner cartridge or a refilled/refurbished one? We tended to find that the refills caused problems in some cases. The customer was free to use these cheaper cartridges but if we found the problem was due to the cartridge; leaking toner, imaging drum scratched/worn, we would charge the customer for the cleanup and fix on a T&M basis. Try a different HP supplied cartridge first if possible (or a different "anybodies" cartridge for that matter. It'll tell you whether the cartridge is duff or not.)
Instructions for replacing the drum look as simple as I remember (I was fixing older desktop laser printers among other things; LJIII, LJV, 400,401, etc) Toner spills could cause some pretty weird problems so I'd definitely check at the right side once the cart is out. Spilled toner can melt near the fuser and form blobs which could cause the jam. We found the blobs were good for producing crumpled prints as they deflected the paper!

I'm not sure if this video is of any use, the printer shown has separate OPC drum and toner cartridge. You can also sift your way through the service manual, all 1328 pages, to see if it offers any better solution. Good luck!

Play Bonny!