White spots in black unit of Ricoh Pro C900

[espastech]

Hi again

I have a similar problem as Hadster has in this post:

http://www.copytechnet.com/forums/ri...pots+ricoh+900

The difference is that I have it in a Ricoh Pro C900, so I guess that it cant be the transfer roller, because other colors (CMY) appear correctly printed. I have replaced the black developer (with only 200.000 copies, 25% of its capacity) but it didnt worked. The white spots keeps appearing, specially in low gray tones. The lighter is the gray, the more spots appear.

What can it be?, the drum is almost new too, the developer is new... and the ITB and transfer well are working well with other colors.

Thanks in advance. Best regards.

[slimslob]

Re: White spots in black unit of Ricoh Pro C900

In the ITB, there is a transfer roller for each color including black. This is the roller that presses the belt against the drum. You have to remove the belt from the unit in order to clean the rollers.

[espastech]

Re: White spots in black unit of Ricoh Pro C900

They are totally random, some copies have less white spots but other are completely filled by them. I'll check the transfer roller in the ITB.

[espastech]

Re: White spots in black unit of Ricoh Pro C900

In the ITB, there is a transfer roller for each color including black. This is the roller that presses the belt against the drum. You have to remove the belt from the unit in order to clean the rollers.

Thanks Slimslob for your help.
I fixed he problem with your help: the intermediate transfer rollers were "hard" (not soft), covered by dust and in general, very used. I changed them and the black unit prints perfect again.
Thanks a lot