IPG-HP Color LaserJet CM6040 CM6030 CP6015 : SHThompson :Re: Color LaserJet Paper Skews

[Cbert]

http://h30434.www3.hp.com/t5/Other-Printing-Questions/Color-LaserJet-CM6040-CM6030-CP6015-Paper-Skew...

This is an informational post documenting an issue I fixed a few months ago, but did not find the answer to the problem online.

The issue was reported as a CM6040 that had a stacker problem.

The CM6040 prints up to Tabloid sized paper, so it normally feeds letter size paper long edge first, in this case the issue was with letter size paper.

The pages were skewing as they were being stacked, and then when the stack was stapled the skewed pages would be missed and fall out of the stapled set.

I inspected the stacker and did not see any obvious problems, then tested the machine.  The stacker on this model outputs the pages, then knocks them towards the back of the machine with a paddle, then they hit a spring loaded backstop.

When the paper was knocked backwards and "Flying" towards the back of the printer it was turning slighty resulting in it landing skewed.  In many cases the paper was "Flying" over previously stacked sheets so the only parts of the printer involved in the stacking were the paddle and backstop.

There were no mechanical issues with the stacker.

After inspecting the skewed sheets it was discovered that they had wrinkled lines towards the center of the sheet parallel to the direction of paper motion, this appeared to be poor quality paper, but after better paper was acquired the issue persisted.

Replacing the Fuser resolved the issue.

Since that repair the same customer has had three other CM6040 printers wrinkling paper due to the Fusers running too hot, fortunately for them all their machines had Care Packs. (List price on a CM6040 Fuser is $710, at least that's what it was in August 2015)