Bizhub c652 grey background patches on internal prints

[hondapol]

I have a c652 that is producing a grey patch in 3 areas front centre and rear in feed direction, the wierd thing is that although it is on internally generated test charts the patch enlarges and still appears 3 times on an A3,The background gets increasingly darker over 20 prints and there are negative images of previous lines within the background so I suspect something around the quenching lamps. Machine has new drum and dev units and problem does not appear if I do a copy in any other colour. Any input would be much appreciated.The attached images were run in test mode without changing any settings,all I did was pull out the a3 tray so that a4's were produced and both images were the last of 20.
c652-a3.pdfc652-a4.pdf

[Gaffers01]

Re: Bizhub c652 grey background patches on internal prints

Looks like a faulty transfer roller from that print, i wouldnt think it would be the quenching lamps though it would cause more conformity acroos the print.

If you roll the piece of paper so the start of each mark is aligned it will show you what size of roller is causing the problem

[hondapol]

Re: Bizhub c652 grey background patches on internal prints

Hi Gaffers,
Thanks for the post, problem with the roller thing is the patch is 8cm on an a3 with a 10.5cm clean area but on an a4 the patch is 5.5cm with a 4cm clean area.

[Synaux]

Re: Bizhub c652 grey background patches on internal prints

Try a stop test to try and see where it is originating from.

And I would try a different IU if you have one available.

[hondapol]

Re: Bizhub c652 grey background patches on internal prints

Try a stop test to try and see where it is originating from.

And I would try a different IU if you have one available.

Hi Synaux, thank you for your input. Both the drum and dev units have been replaced after this fault came to light.
I am going to return today and try to eliminate transfer and laser units so i will keep you informed.

[hondapol]

Re: Bizhub c652 grey background patches on internal prints

Been back today, swapped transfer belt and roller. covered both laser and quenching lamps but fault persists regardless. Going to go back with an HV pwb to see what happens.

[cayyell]

Re: Bizhub c652 grey background patches on internal prints

Hi, gotta hijack your thread abit

Did the HV pwb solved it? Or is the lamp?


I have a similar problem, but the difference is, it only happen when making a colour print. Black print is fine.