WC 7855 uneven density

[MHeon71]

I have attached an image of what it is doing. If feel that it is electrical and possibly the wall voltage. Xerox tech seemed not to want to entertain that possibility, because it is rated for +/- 10% of power.

There is an ESP that is hooked up. The voltage that I am reading at idle is 116 VAC and low 114 VAC during copying. They say the first sheet normally comes out fine and the rest of the copies start to show the issue.

I have flashed the firmware, but not much else. I am stuck on low voltage, but if you have seen issue, please let me know. As you can see in the example, the pattern is not constant, so I would not consider it a drum, DV or other physical component.

Any help would be appreciated.

[drewzif]

Re: WC 7855 uneven density

Do all pages for the print defects troubleshooting look like this? My first shot would be to re-seat the ITB or replace it.

[MHeon71]

Re: WC 7855 uneven density

Not all pages. The first page looks fine. I replaced the ESP surge protector and only 1 page out of maybe 30 came out that way. I can definitely reseat ITB connectors and if need be, replace.

Thanks for the help.

[drewzif]

Re: WC 7855 uneven density

Good luck!

If you have a 7800 or 7525/35/45/56 the ITB should be the same also to try a swap.

[JrTech]

Re: WC 7855 uneven density

MHeon. Thank you for the pic. It shows us only that you are getting banding, I also see a dogear on the upper left hand corner of the doc. What color is that supposed to be. Can only really look at the CYMK colors from the machine and give a better idea. I would look at a developer mag roller. Make a copy of the Supply Usage Profile page in a single color CYM (Under color tab - more - single color - select color) and do a BW copy as well. Once printed out it will give you a better idea what color you are dealing with. Make 50 copies. Reason is you want to rule out the developers before you go chasing board, power issues. What is the life count on the developers?

[drewzif]

Re: WC 7855 uneven density

The scan to me looks like the GREEN page in the solid fill test. If so the banding is happening across yellow and cyan, making my best guess the ITB if all colours have this same issue.

[MHeon71]

Re: WC 7855 uneven density

You are correct with happening across all colors. I reseated and replaced the ITB with the same issue. I started messing around with the 2nd BTR and I have received some success. I placed a rag behind the 2nd BTR for testing and now I have run 50+ copies with no uneven density. It does have streaks in it, but only seem to occur in light colors. I will replace the left door cover assembly.

[MHeon71]

Re: WC 7855 uneven density

I changed out the ITB, left door assembly and the 2nd BTR without success. I have replaced the MOB assembly and it has been at least 2 weeks with no customer calls.

Thanks for the help.