the upper left corner of each page is bent

[dg1107]

The upper left corner of each printed page is bent.  Just started doing it.  What's the problem?

[Jim_Asman]

The first thing I would try is to flip the stack of paper in the tray over. If that doesn't change anything, then I would assume there is a blockage of some sort in the paper path.

[dg1107]

Thanks for the post but I'm already assuming something is blocking something.  I have changed paper, turned it upside down, sideways, run my hand over anywhere I can and have found nothing obvious.

[Jim_Asman]

What happens if the paper goes through the duplexer?

[dg1107]

I load the paper in the paper "tray" that slides in and out on the bottom of the printer and print from there.  I'm not sure what you're referring to as through the duplexer.

[Jim_Asman]

You said your printer is a M402dw. The "d" says that the printer ia capaple of dueplexing; i.e., the printer can print on both sides of then paper automatically. Your printer has a built in duplexor. You may have to tell the driver that you do have a duplexor, although you would think it would be that way with the install.

Assuming it is set uo propertly, you should get a checkbox in the print dialog for "print on both sides". Check on that, and also check on the binding edge, the long side for portrait mode. Send the printer a job that is two pages duplex which will use a single sheet of paper. As the paper goes through the printer twice as it were and I believe the second pass has the sheet go through the printer "upside down." So in duplex, do you get 2 bent corners?

Have you tried different paper stock? I assume you are using typical 20 or 24 pound paper. I once had a problem using 3hole prepunched paper the would print fine simplex,  but regularly jam duplex.

The point of all of this iis to determine where in the paper path is the corner being bent, probable somewhere where the paper is looped to change direction. Maybe coming out of the feed tray or some other turn around point in the paper path. It is possible that a roller has become dislodged slightly. If your printer has a rear exit in the back of the printer, exiting there may help the understanding of where ithe problem is. I suspect that most printers DO NOT have an optional rear exit. 

[Valsimot]

You can also print a few pages from manual tray to see will bend, in that way we can determine if a problem only in tray 2 or both trays.

[dg1107]

Thanks for the comprehensive reply and info, Jim.  Really appreciate your efforts. 

Going from last to first, I did print a couple pages from the manual tray and the corner came out NOT bent.  Yippee!  That narrows the field a bit, I hope.  Still follow the other suggestions??

[Valsimot]

We now know that the problem occurs only when printing from tray 2.  Your next step is to remove tray 2, remove toner place printer on the back side so you can see underneath the printer and examine left side of the paper path for foreign objects, paper leftovers.

Also if you have a heavier paper you can print one page from tray 2 maybe the heavier paper will push out any obstacles that are bending paper.