[Misc] MX 4101 Smudges on black only

[Jammed]

Weird
I can run any single color or any full color job, no smudge line appears at all.
Run black copies. First one good, all of the others following have a bar, solid smudge line (blur) down the page about 9" from lead edge, black line.
Replaced T-belt and drive gear, drum clutch drive assy'. replaced black drum unit. replaced fuser.Adjusted a lot of the timings to no avail.
Scratching my head on this
Anyone see this before?
TIA
-Steve

[sharpie]

Re: MX 4101 Smudges on black only

I fought one for a week, wound up adjusting the registration buckle and black drum timing to resolve.

[Jammed]

Re: MX 4101 Smudges on black only

Thank you