Toshiba eStudio 4511 color quality

[Guest]

I have 2 toshibas estudio 4511's. One is making bad color copies (see attachment) the other is fine. I tried making adjustments according manual, but didn't get much better. I changed the transfer unit, image quality sensor, the color developer unit (which changed a little), and even the drum unit. I used the good machine to change the parts but still nothing. Black and cyan are coming good though. Any help will be appreciated.
Please see attached files.
Thanx

[copytechman]

Which transfer unit? The one on the right door or the stinker that sits above the drum unit? Looks like a possible drive anomaly to me possibly in the 1st transfer area.. I've seen those drive roller bind up on the cleaning brushes (what a joke) and causes a narrow pitch banding much like what your samples appear to look like.

Regards!
A.

[tcnet]

First, I replaced the big one (over the drum unit) and didn't amke any change, then I also interchanged the 2nd transfer roller and the image quality sensor on the right door, the copy got better but stil with the liness. That's the last thing I changed. After that I made the forced auto adjustment and the copies comes like the pdf files posted before.
Does it have to do with the charge unit. If so, how can I restet it or adjust it?
Thanx

[copytechman]

Lemme think, are those bands perpendicular to the paper path or with it? Cuz it makes a difference!! U didnt place and paper path direction arrows on your samples!


Regards!
A.

[tcnet]

The lines are perpendicular to the paper path

[copytechman]

Nuts, usually lines with paper path typically can be charger or xfer issues.. but perpendicular indicates drive anomaly.. my best suggestion is the do a full colour 11x17 copy and stop it b4 it transfers to the paper to look @ the image on either the drum or belt.. they did mods to the xfer drive to improve its performance... not fun.. Other than that.. perhaps a drive issue with the dev drive but then it'd be all colours too.. I'd try the stop test... etc...

Regards!
A.

[emujo]

Its interesting that the last 2 colors to be laid down (C and K) look pretty good, but Y and M are crappy so my 1st step would be to see where the problem starts. Pull the inner cover off to expose the xfer belt and run a calibration test chart. Watch the lay down process as each color is put on the x-fer belt. Does the quality defect show at this point? If no, the problem is during 2nd transfer and you can eliminate drums developer stations and xfer belt. If yes, my guess would be a problem with the Y and M developer units. Maybe they are too close to the drum (gap can be checked and set). Color devloper drive seems to be OK or you would have the same symptoms with C. Could also be a problem with the teeth on the revolver unit. Looks like developer is bunching up and causing chatter. With the magenta line at the top of your samples, I would start with this unit. Hope some of this helps. EMujo

[ToshibaTech]

Eh... kinda hard to tell from the scans but I'd check the revolver unit for a chipped tooth or any play (there should be none) side to side or rotating. Weird that it doesn't do it on Cyan, of course black wouldn't be affected by the revolver. Might just the the way it is rotated on cyan is still tight.