CLJ 4650 no black

[theengel]

I've got a CLJ 4650 that doesn't print black. All colors print correctly. I did a stop test, and there was no black image on the black drum. No error codes. All the drum & ctg connectors seem to be fine. Any ideas?

[Lance15]

Check:

Developer Disengagement Plate - RB2-8239
Spring tension - RS6-2537

Came across a couple, years ago, where some of the lower teeth on the DDP were broken and not working right. Have also had a couple where the spring breaks. You can't see the broken teeth on the DDP unless you remove it. A sign that the teeth are broken are unusual noises when the plate moves up and down.