Xerox Workcentre 7775 - Mystery Spots

[mross17]

I have a Xerox 7775 and it's printing these strange gray bullseye spots all over.

I changed out:
All the Drums
All Toners
All the Developers
IBT Belt
Fuser

The spots are much lighter now, but it's still showing up. The first 20-30 sheets are fine, then as the printer heats up, the spots start showing up, getting progressively more pronounced as more pages print. The spots are only black.
Screenshot 2023-11-17 at 4.23.57 PM.jpg

After changing everything, the spots are much, much lighter with fewer showing up. The spots that show after the change of parts are in the same locations as before changing the parts.

[shinchan]

Re: Xerox Workcentre 7775 - Mystery Spots

I have a Xerox 7775 and it's printing these strange gray bullseye spots all over.

I changed out:
All the Drums
All Toners
All the Developers
IBT Belt
Fuser

The spots are much lighter now, but it's still showing up. The first 20-30 sheets are fine, then as the printer heats up, the spots start showing up, getting progressively more pronounced as more pages print. The spots are only black.
[ATTACH=CONFIG]60537[/ATTACH]


After changing everything, the spots are much, much lighter with fewer showing up. The spots that show after the change of parts are in the same locations as before changing the parts.

have you check the rubber roller inside the IBT Belt?

[mross17]

Re: Xerox Workcentre 7775 - Mystery Spots

have you check the rubber roller inside the IBT Belt?

I changed out the entire IBT belt assembly. The problem has become much lighter - not as pronounced, but it's still there.

[adriansto]

Re: Xerox Workcentre 7775 - Mystery Spots

I changed out the entire IBT belt assembly. The problem has become much lighter - not as pronounced, but it's still there.

Presuming the spots are also on ibt belt check if the ground pad for black drum is in good working condition and electrical contacts of the drum itself and on machine are clean.earthpad.jpg

[mross17]

Re: Xerox Workcentre 7775 - Mystery Spots

Presuming the spots are also on ibt belt check if the ground pad for black drum is in good working condition and electrical contacts of the drum itself and on machine are clean.[ATTACH=CONFIG]60556[/ATTACH]

Ok I will check that.
The printer is new - like only 75 pages on it. It's spotless inside.

I just printed a 13x19 sheet and was able to measure the distance between the spots and they are all exactly 7 7/16" apart.

[xcopytech]

Re: Xerox Workcentre 7775 - Mystery Spots

If distance is 188mm then black drum is problem.
If your machine have only 75 pages it is look like that someone replace nvm battery and reset counters.
Also check black developer assy

[mross17]

Re: Xerox Workcentre 7775 - Mystery Spots

If distance is 188mm then black drum is problem.
If your machine have only 75 pages it is look like that someone replace nvm battery and reset counters.
Also check black developer assy

We replaced the black drum with used drum from another printer and replaced the black developer assembly as well. But it was used too.

What are the odds that the spots are in the same exact spot with 2 different drums and 2 different assemblies.

We have 2 printers - one is jamming - so we have been using the parts from the jammed machine in the newer machine. We took out all the drums, all the developer assemblies and put them in the new machine. But the spots are in the same place. They are much lighter now, they are like shadows.