[CQ] Bizhub 350 - Unknown shading charge

[masterofpatience]

I have a Bizhub 350 which has had the drum unit replaced twice, and the drum and blades replaced 3 times, the transfer roller replaced and the developer changed. The mirrors are clean, and the path to the imaging unit appears to be free of barriers yet I still have a shaded REAR (not trail) edge on the image as it comes from the machine. I have considered replacing the developer unit itself but the problem appears to be a charge coming from somewhere as the shadow appears on the drum even after the copy is completed. Normally I would attempt to get into the laser unit itself and try to clean the glass between the polygonal motor and the drum but I can find no way to easily remove the laser assembly from the body of the machine.
Any recommendations would be appreciated before I get myself deeper into the machine.

Thanks

[Hansoon]

Re: Bizhub 350 - Unknown shading charge

Dirty laser slit glass would not make a shade but light copies. However if you want to clean it:

shutterrip.jpg

How is the rear drum spacer collar btw? Is the collar wiggling on the shaft of the mag roller? Is de rear of the drum scored or scratched? Is the seal at the end of the mag roller damaged?

Hans

[masterofpatience]

Re: Bizhub 350 - Unknown shading charge

There is a definite wear pattern in the drum where the shading occurs, about an inch in from the edge of the hub. The image only shows up (naturally) on 8.5 X 11 or 11X17. I considered replacing the developer unit itself but didn't want to make the investment if it wasn't necessary.
BTW...Thanks for the laser access image!
Wouldn't the rear drum spacer be replaced with the new complete drum assembly?

Dirty laser slit glass would not make a shade but light copies. However if you want to clean it:

http://img263.imageshack.us/img263/2030/shutterrip.jpg

How is the rear drum spacer collar btw? Is de rear of the drum scored or scratched?

Hans

[Hansoon]

Re: Bizhub 350 - Unknown shading charge

How much is on the developer unit? If they are not too old its worth to rebuild them. For sure the rear drum spacer collar is worn but you can get an improved version from Densi #7020186

Hans

[masterofpatience]

Re: Bizhub 350 - Unknown shading charge

Thanks! Will investigate that later today.

How much is on the developer unit? If they are not too old its worth to rebuild them. For sure the rear drum spacer collar is worn but you can get an improved version from Densi #7020186

Hans

[b3p0]

Re: Bizhub 350 - Unknown shading charge

I'm interested in the solution as well.
I have BH350 that has a similar shading issue. However I have replaced the developer, and put a re-manufactured drum and blade assembly on it, and changed the drum cleaning lamps from a known working machine. The issue now only occurs after long jobs of 500 + prints.
I've also looked over and cleaned all contacts for the transfer section and roller thinking maybe something is getting warm and loosing contact after long jobs.
Luckily the customer doesn't have any 500+ print jobs that will happen for another few weeks.

[masterofpatience]

Re: Bizhub 350 - Unknown shading charge

@b3p0
I will let you know if the spacer resolves the issue. Mine appears at first copy and was noticed when running print jobs originally then we noticed on copy jobs as well. Should know later this week.

I'm interested in the solution as well.
I have BH350 that has a similar shading issue. However I have replaced the developer, and put a re-manufactured drum and blade assembly on it, and changed the drum cleaning lamps from a known working machine. The issue now only occurs after long jobs of 500 + prints.
I've also looked over and cleaned all contacts for the transfer section and roller thinking maybe something is getting warm and loosing contact after long jobs.
Luckily the customer doesn't have any 500+ print jobs that will happen for another few weeks.

[fixthecopier]

Re: Bizhub 350 - Unknown shading charge

What Hans is talking about is common on all Bizhub 250/350. Usually the ones I have to change collars on will show a scratch on the drum just in from the right side of the drum, caused by the worn out collars. [check out Han's avatar, it shows the better collars.]

[eg101]

Re: Bizhub 350 - Unknown shading charge

[QUOTE=masterofpatience;286
Wouldn't the rear drum spacer be replaced with the new complete drum assembly?[/QUOTE]

The spacer is on the developer unit, not the drum unit.

[Hansoon]

Re: Bizhub 350 - Unknown shading charge

Here is the collar (damaged old type) located. It shows also the seal and the scored drum.

CollarWear1.jpg

Hereunder a similar unit with intact drum, seal and collar

Hans