di850 HELP!

[xpress]

Cannot get my 850 to not have backround.


All settings are reset - no odd settings
New drum and dev (until it gets light)
New blade
Cleaned that soft roller under blade many times - dumped unit
Cleared toner hopper and dump path

The drum never looks like it has spotting on it or anything, I cant seem to find where it is coming from. All my parts are clean and undamaged, and I can't stop the machine in cycle and find the part, it looks good?

Nothing on solutions

Any ideaS?

[minimerlin]

Are you using genuine toner? Have you done the full set up for new drum / dev? Have you got a good drum earth, new charge grid/corona?

[xpress]

New drum, starter, process adjustments. Counters list the 1st row as all under 14k prints

they get light with no background, but the problem is when I add toner they become dark, but with tones of background everywhere. Goes away as copy's fade

[minimerlin]

Can you upload the adjustment printout sheet...I have not had this problem, maybe a bias or charge?

[datapresstecnica]

We've seen these a few times with defective drum potential sensors. Does Auto drum potential adjustment finish with no error? Also could be that drum potential control (SW Switch 06-7 in 2-5 mode) is disabled (Switch should be in 0 when it's active).
A bad corona could cause something like that too.

[xpress]

Thanks by the way, Never knew about the list, they look normal or around it, but thanks for looking!

You can probably see the background on the paper


And thanks datapresstecnica, SW is off (0) and the Auto drum potential adjustment finishes quickly and quietly, except for a quick motor noise.

EDIT: Yes Minolta toner also

[minimerlin]

Looking at the printout I cannot see anything wrong with the settings...but the background seems to be darker at the top of the print, is that the case on all copy/prints? If so I would renew the grid and charge wires, and also make sure that the charge corona unit is correctly latched onto it`s lugs....I have had uneven backgrounding if the unit is not the same distance from the drum over the complete length.

[datapresstecnica]

I don't know how accurate this might be, but one of our techs says there's a bearing in the magnet roller of the dev. unit that may cause poor bias.

[xpress]

Well il rip it apart and look at at, at this point im desperate. I took out the whole thing and checked all the grounds, ones on the flywheel, all sorts of things.


~new corona unit


Its almost gone,but I can still see some darker spots. It should have 0 background, so I can't put it out in the field yet, damn POS wasting my shop space

[manuelcorrea]

We had a Di 850 with a similar problem. Tried changing developer first with no luck.We put in a new developer unit and that took care of the problem.Hope that helps!!

[Rolandito]

Hello , everyone i solved my background problem, changing the drum bearing, the problem is that the drum is not grounding well. or put a little metal grounding the bearing.