250ci no black

[copiman]

I started with a C7000 code. All toner motors and dev motors were turning. The black dev unit was full to the top of where toner enters the dev unit. I swapped dev unit from shop machine and the got dev motor code. Swapped out dev motor and code went away. Now I have no black output and its toner entrance area is packed as well. Im thinking maybe something in the dev drive is the culprit. I have never dug in and removed drive unit area for the dev and no instructions in this area in the serv manual. Anyone seen this before?

[darry1322]

Check the drive coupler for the black developer unit. There is a pin that can fall out of the drive coupler and cause you to lose developer drive.

[darry1322]

35249

Here's a picture from the parts manual of the coupler assembly. When the drive rotates in the reverse direction ( clicking noise ) to vibrate toner in the developer unit , I think over time the coupler sleeve ( 5 ) loosens until it slips off and the pin ( 105 ) falls out and the couple comes apart. My theory anyway.

[copiman]

Sounds reasonable. How would you get to it? I was thinking removing the drive unit but nothing in the manual on it. I take it you have done this before so how do I get to it to check the drive?

[darry1322]

Sounds reasonable. How would you get to it? I was thinking removing the drive unit but nothing in the manual on it. I take it you have done this before so how do I get to it to check the drive?


Pull the fuser, belt, black drum and dev. Look inside the machine where the dev unit would get it's drive. Check the coupler and make sure it's still together. Check the next one over for comparison.


If the coupler has come apart, you'll have to go in from the back. Remove the power supply, drum motors, dev and cleaning motors, HV unit, right and left drive units, then the drum and dev drive unit can be removed. It takes about half a day if you haven't removed most of these before. Make sure you pay attention to all the connectoers coming apart and going back together. Easy to miss something and have to do it again.


We have started using a bit of adhesive when slipping the collar back on the coupler assembly to hold it together better. We had one slip back off soon after the initial repair. Nothing to do but do the whole thing over again.

[Reed]

try to go through the front to fix the coupler ( if at all possible) going through the back is kind of a pain. I pulled it from the back then realized I could have done it by removing the fuser, transfer belt, black drum and developer unit.

[copiman]

Thanks for the info. I will take a look. Sure don't want to take the unit out.

[blackcat4866]

I always wondered if somebody would ask: =^..^=

[copiman]

I always wondered if somebody would ask: =^..^=


Thank you very much. Being the only technician its helpful to get support from other techs.

[copiman]

Here is the outcome. Turned out to be the BK dev motor. I totally confused myself about what motor is what. Although it was really simple, I made it worse. The good thing is I learned a great deal and got instructions on how to take out the drive. Thanks everyone for your help.