BIZHUB 750 bad image quality on the back side of the duplex copies.

[cristian]

When a make copies on duplex (face and back) I have a bad images on the back side of all copies.The face is acceptable.The problem became more visible when i make A4R copies , the quality is even more bad...Also appear on printing from computer....and before the entrance in the fuser...
Some ideeas ?

[SmellsHot]

Replace Developer.....

[JustManuals]

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Paul@justmanuals.com

[cristian]

have 6000 copies with the developper and the drum...

[Darren King]

Run about 30 skyshots and then run the drum peculiarity starting with cartridge set and then in order that is on the screen. That is how I get these pigs to stop over toning. It usually last from 25,000 to 75,000 pages before I have to do it again. I know it ain't real scientific, but it seems to work.
Hope this helps.
Darren

[cristian]

[QUOTE=Darren King
my problem is exact the opposite one.The front copy is acceptable as density, but the verso goes to near a white copy

[Darren King]

[QUOTE=Darren King
my problem is exact the opposite one.The front copy is acceptable as density, but the verso goes to near a white copy

Sorry, you didn't mention that the image faded. I assumed that it was over toning because that's what these machines do.

[SmellsHot]

What if you do a 2-2 with only an image on the 2nd page? I'd make sure your tcsb sensors are clean as well as your charge and T&S wires. Then I'd run cart set, run back through the auto adjustments(and make sure that all are "ok"). Then run 50 dbl sided sets of the #12 test pattern........
If you still have problem, please upload photo

[cristian]

I have walk through the steps indicated.
Thank you for the idea.The quality is improved with 40%, but unfortunately it is not enough good…
Another details>
- Grid OK
- Wires – replaced and OK
- Developer and drum 6000 copies
- All the sensors after the autoadjustments are OK
Perhaps will help some idea about the manual data, for each setting.The photos are mede after the tests with>
Charging main 180
Transfer main 115
Separation AC 100
Separation DC 100
Grid charging 120
Bias voltage 215
LD1 offset 45
LD1 Bias 191
And
Max dens 27
Laser diam 27
I attach the scans
And as PS, the quality during the 50 tests was changed from the 20 test in better and in bad after that till the end…
First is the original, the second is the first face and the third the second face....Copies made with normal density settings.
208652086620867

[cristian]

Have found the problem....The guy has change the positions of the 5 screws from the transfer guide plate.Does anybody knows if is there any standard position for those screws?