Duplex Print

[fil]

I have 10 HP Laser Jet 9050dn. My question is this, I have some form of defect on the paper when duplexing it is usually a corner of the paper has black ink of some type hard to explain but they all seem to do it accept two. I cleaned duplxer and replaced toner and still no fix have any ideas? I have a big job coming up next week which involves duplexing and I cant get them to print out without some form of defect on the paper. Thanks

[cs_steve]

This might be a fuser problem ... Try swapping a fuser from one of the printers that DOESN'T have a problem... see if the problem goes away...

[fil]

Is there a way to clean the fuser?

[fil]

I also replaced with good duplexer and problem still there. Its right at the top edge of the paper its black something. I tried to clean the two rollers inside the the duplexer and still nothing.

[redcow]

Run a 1/2 test page. See if the defect occurs before or after fuser.
Try the MFT.
Try paper path test/all trays. Do they all fail?

This is interesting, get back with results

[prntrfxr]

I agree with red cow. See if its happening with all trays or just one. Hold up the page to the light. Is the test page borders on side 1 match the test page borders on side 2? Try adjusting registration in the PRINT QUALITY MENU, see if that changes the mark.

[MichaelTech]

Well, is it all 10 printers having this?
If using a 2000 sheet feeder, the the transport assy. may be skewing enough to catch the corner of the page. The smudge has me thinking that it will be in the fuser area, or under the registration assy. A toner not seated well might be the cause. As redcow sez, see if it is before the fuser, and check before it goes to the duplexer.