Vertical line when scanning via ADF

[BobbyM56]

Hello. When scanning via the ADF on my HP Color LaserJet Pro MFP M479fdw I get a solid, vertical black line in the exact same spot traversing the entire page. I have cleaned the the narrow scanner glass strip on the left side. I have cleaned the flatbed itself. I have used canned air to blow out the ADF. The odd thing, to me anyways, is that the vertical black line presents itself in multiple page scans as follows:

*Multi-page, single sided scan: it appears on every page

*Multi-page, double-sided scans: it appears on every other page

There is no line present when scanning via the flatbed glass.

[Valsimot · Accepted solution]

Copy a blank page from ADF, the copy will have line on it, place the copy on the flatbed, the line on the sheet will align with dirt on a smaller glass.

[BobbyM56]

@Valsimot, thank you! What a brilliant, yet incredibly simple solution. I almost feel silly for not thinking of taking the line on the copy to line up on the flatbed to the narrow glass to pinpoint the culprit. Sure enough, despite my many times of cleaning the narrow glass, the line on the copy pointed to a tiny and stubborn piece of debris caught up under the very edge. With the line and a flashlight, I clearly saw the issue and it was easily removed. Again, brilliant, yet so simple. Thanks again!!