Single Black Vertical Line When Scan or Copy Using Flatbed

[cborjon]

Single Black Vertical Line When Scan or Copy Using Flatbed - There is a vertical line is present with scans and copies from BOTH ADF and the FLATBED scans.   I get why lines happen with the ADF, but what could cause a line when just using the FLATBED to scan and copy?   I tried the powering down the printer, unpluging it from both the printer and the wall and waiting 30 seconds and that did not work.   Is the issue the the scanning bulb mechanism?

Attached is a diagnostic SCAN.  See the faint vertical line above the #2.  The darker circled segment was made by a pen as I tried to zero in on "the line" to clean the glass.  It is not dirty glass (at least on the outside).

scan

Also attach is a scan of a copy made with the printer ADF open

open printer copy

[Valsimot]

It could be some dirt or dust inside the scanner on the lamp or optics.

[cborjon]

Yeah...but how did it get in there?  

It was working fine before.....

[cborjon]

Ok....I am going to keep posting in hopes that I get a useful answer because eventually I think the scanner assembly is goign to need to be replaced.

[cborjon · Accepted solution]

I say eventually because, now the line is gone!
 

What is different?   Well I was trying to activate the Readiris OCR software that come with the M426 and it would not automatically load an activation code.  The Readiris site says try to do the activation with USB connection.   So I connected the the M426 with a USB cable.   During the troubleshooting phase, when I disconnected the power.  I also removed the USB cable but I promply plugged it back in.   Overnight I gave up on Readiris and the M426 and started doing research on replacing the scanning mechanism. 
 
This morning I woke up and went over to the printer and did an open ADF copy to see if the issue was still there.   It was but the line was fainter.  Just my imagination.....or it turns out maybe not.   A couple of hours later, I started a the big scan job (the original reason I originally started using Readiris and noticed the issue with both Readiris and HP Easy Scan).  This scan job was done from my office in another part of the house via WiFi (not USB direct).   I gave up on Readiris.   However, much to my suprise the vertical line is gone!   NO LINE with the ADF or just using the FLATBED! 
 
Similar to the dubious static build up in the power cord causing vertical lines (HPs troubleshooting steps), could there have a problem with the USB connection?  I could try it with the USB cable again to see if the problem comes back, but I am not going to chance it.  This time it might not reverse itself after a nice long autosleep without the USB cable connection.