paper feed issue resulting in bends and some smearing, offsetting of 2nd page when duplex printing

[Erikfj]

paper feeding when duplex printing results in a slight bend, 2nd page is offset (late feed) by 1/2 inch, some ink smearing as a result of the bend with ink on other side still wet.  Been printing well for over 10 years.  New print heads 6 months ago.  Problem just noticed today, wasn't happening a month ago (or ever before this).  Have cleaned all accessible rollers per HP instructions.

[Erikfj]

Some additional info.  The print offset appears to be on both front and back, and can be explained by a "late paper feed detection", if that is possible, where the paper is farther along the path than the printer thinks.   The result is the front page printing is delayed down (about 1/2 inch lower than expected) and the back side as the printing starts from the other end is delayed "up", so the top of the printed page is very close to the top edge of the paper.

The kink in the paper is across the entire page (left to right), at about 3 inches from the feed end (top of paper on front side, another kink at 3 inches from the bottom of paper on back side).  When a single page is printed, the same delay and single kink as in the front side of a duplex printing.

[Erikfj]

Additional info.....  the same symptom when printing a "printer status report" from the front panel.....  it is obvious that the page is about 1/2 inch down the page, the symbol at the bottom being half cut off.  This confirms it has nothing to do with any pc or os interface or driver software.  The problem is the paper detection during the feed process is delayed.

[Nal_NR]

Hi @Erikfj,

Welcome to the HP Support Community. 

I'd like to help!

Splendid analysis and remarkable patience were shown. It is immensely appreciated.

This looks like a hardware issue. If you have performed all the steps mentioned in this document and still having issues, I request you contact phone support. 

For that to happen, we will give you additional instructions/information via Private Message.

Please check your inbox on the forums page for the private message.

If the information I've provided was helpful, give us some reinforcement by clicking the Accepted Solution button, that'll help us and others see that we've got the answers!

[Erikfj]

Thanks, but this "help" wasn't help. All the trouble-shooting info you provided are steps already taken.  I need to hear from someone who understands how the leading edge of the paper is sensed within the printer, and how the top of the printed area (the distance from that paper edge) is determined.  Either the sensing of the edge, or the measurement of the offset from the edge, is in error.  This error (an offset) occurs every time either side of the page is printed,  whether from an external PC providing the text or image, or when it is an internally generated report with no external device connected. It is either a sensor, or the controller, and I would like some help from someone familiar with determining which is at fault so I can order the correct part.  As no "service manual" is available, only "lists of replacement parts" from various vendors, it would be helpful to have the additional insight to this function.

[Nal_NR]

Hi @Erikfj,

Welcome to the HP Support Community. 

I'd like to help!

As we have limited support boundaries in the support community as of now. I would request you to contact our HP Support Engineers who should be able to sort this out.

For that to happen, we will give you additional instructions/information via Private Message.

Please check your inbox on the forums page for the private message.

If the information I've provided was helpful, give us some reinforcement by clicking the Accepted Solution button, that'll help us and others see that we've got the answers!