Konica 7145 smudge

[DOE]

I have a 7145 that leaves what looks like a thumbprint along the edge of paper. Its size of thumb and has lines through it. Exact same pattern everytime. Replaced drum, corona and blade still have smudge. Stopped paper as it got to drum and could see that thumbprint image on drum. Happens on rear edge and along the edge of paper. Going to take a different drum unit over and shaft to see if something could have been bent? Any ideas would be apreciated. Will let you know if unit worked or not. Thanks

[mrwho]

If you see it on the drum, then someone's thumb has been on the drum and the skin's oil is leaving that mark. Try cleaning it with a soft cloth.

[DOE]

new drum. you can only see that image when you make a copy otherwise its a clean drum. also appears on test prints. its not a thumbprint but thats what size it is. image appears with old and new drum. exact same mark

[minimerlin]

Does the mark have a specific distance between repeats? Possibly problem with dev tank/ mag roller?

[mrwho]

Is it visible if you scan it? If so, post here an example. Also, minimerlin's question is also relevant.

[DOE]

Replaced developer unit and drum shaft and bearing still have problem. Image repeats every 6 inches or so. Image is on drum when you stop copy at drum. Internal test prints come out same way so optics are eliminated. Its the size of a nickle and has lines through it. Exact same pattern of lines in smudge everytime. No its not a thumbprint on drum. New drum. Happens along rear edge of paper

[mrwho]

When you said you replaced the corona, I'm assuming you were refering to the charge corona, right? And you replaced the entire corona, not just the wire and grid, correct?

Still about scanning the defect, can it be done?

[DOE]

yes i replaced entire charge corona. i dont have a way to scan at this moment. i really apreciate your input