Utax cd 1325/1330 Bad Copy

[quitech]

HI
Greeting to you all, i have problem with Utax cd 1325 and 1330, copy quality problem. this machines are making blunt copy as if the drum need to be refresh but if i refresh the drum it became wost. i swap drum unit,developer unit,Hvt from working machine to this machines still the same, i have been cracking my brain for past 4 good day trying to put this machines in other still no good result.

Please friends any idea will be highly appreciate because i am going back to the machines tomorrow
Best Regards Quitech

[AlbertK]

I have had a few problems with the transfer units on these machines. Check the springs on the ends....could they have been swopped arround? Did you swop the maincharge units as well ? Are the bias settings (U101) correct?