Newbie at scanning and having issues

[SimonBestia]

Hi everyone!

I recently bought an HP DeskJet 4120e and have been using it to scan actively since I got it in the past few days.

In the last few pages I've noticed these vertical lines of some kind.
They're always on the same spot (more to the right if the page was at a different orientation).
Looked up that it could be glass dirt but they're there in the exact spot whether I scan through glass or ADF. Not sure if there's elsewhere to clean.

Here is an Imgur link (could not attach the pictures directly due to file size limit) with a picture of the first instance where I could spot the line, then the latest scan, to show that it seems to be getting progressively worse.

https://imgur.com/a/vg5VdwI

Any help would be appreciated, thank you very much!

[MigJmz]

you might have dirt or some particle on the glass and/or the laser itself.

[kitsunebi]

That doesn't look anything like a scan line created by dust.  On an ADF scan, dust lines will typically be perfectly straight and quite thin (not more than a few pixels wide), and they will be a solid color, often red or blue depending on the background color of the page.  You can't see the image on the page behind the scan line, because the laser has been completely blocked by the dust particle.

What your pics look like is scratches on the glass.  Those will be opaque discolorations like are seen in your examples, since the laser light can still pass through the scratch, but it's distorted, causing the discoloration.

Another less catastrophic thing that can cause images like you're seeing is glue.  Sometimes glue from the page binding can rub off onto the glass and cause streaks like you're seeing.  Luckily, that can be carefully cleaned off with glass cleaner and a microfiber cloth.  If it's scratches, you're S.O.L., though.  I'd check the glass very carefully - scratches can be very hard to see.  Hopefully it isn't that though and it's just something that can be cleaned, although I suspect you've already tried cleaning the glass. 

A flatbed scan, btw, shouldn't even have scan lines, since any dust on the glass just gets scanned into the image.  The only way to get streaks like that on a flatbed scan would be to have some sort of scratch or smudge running the entire length of the glass.

[SimonBestia]

Oh, well... that's a bummer since I was almost finished, and the printer is basically brand new.
I cannot see any scratches, but I've tried cleaning the glass with no success.

Thank you for your help in troubleshooting, though!

[PixelBoy]

I have no idea what's going on there, but you can try a few things to rule out possible causes, some more likely than others.

1) Power down the scanner completely, unplug it, and reset it to factory settings. This will rule out internal firmware issues etc.

2) Install a different driver. Either try some generic driver, or use some newer or older version of the driver you are currently using. This will rule out driver issues, obviously.

3) Try scanning using different resolutions and output in different file formats. This will rule out the possibility that the problem would somehow occur only using the scan settings you are using.

4) If you happen to have another copy of the same magazine, try scanning it for comparison. This will rule out the possibility that there is something wrong with the first copy that is somehow messing the scan results. This doesn't usually happen with magazines, but is a common problem with postcards etc.

5) As ridiculous as it may sound, if possible, have someone else scan that page with your scanner. This will rule out the highly unlikely possibility that you are doing something wrong and don't notice it.

If after all these steps those lines are still there... well, you have a broken scanner most likely. Try to have it fixed under warranty. I had once a digital camera that somehow sucked dust inside the lens, which appeared in all pictures. I got it fixed for free. Maybe something similar is going on here.

[kitsunebi]

I think the key to pinpointing the cause is figuring out how/why your flatbed scans and ADF scans are identical (if I understood you correctly.)  I'm not familiar with your printer and have never used the ADF scanner on my printer, so perhaps they function differently from a standalone ADF scanner?  Because an ADF scanner moves the page across the glass while the laser remains motionless.  That's why if there is something on the glass blocking the laser, the scan line will run the length of the page as that spot is blocked the entire time the page is pulled across it.  A flatbed is the opposite - the page remains motionless while the laser moves across the length of the page.  So if there's something on the glass, it will only block the laser at that one single point as the laser moves past it.  The fact that you say you get identical streaks on both types of scans surely holds a clue to the mystery, as it doesn't seem like that would even be possible.

But yeah, on a brand new scanner, you may as well send it back under warranty, because that's huge problem.