HP CM2320 yellow streak scan to PDF only

[MoGoo]

Hello,

HP CM2302fxi scan from ADF to computer and saving to PDF has a yellow vertical line on the left side of the scan/page. Scan to PDF from the glass does not have a veritcal line. So, I cleaned the ADF and the pre-scan strip. I've also changed the yellow cartridge.

Repeated a scan from ADF and saved to bmp - there is no yellow vertical line so I also tested scanning to gif and again no yellow line.

Next tested scan to pdf from ADF with dpi at 300, the yellow line was noticably lessened and lessend further when scan to pdf with 600 dpi.

This just doesn't seem to make sense - shouldn't all scans through the feeder have the same yellow steak, regardless of file save format and why would a change in dpi lessen the issue? But mainly would like to know how to get rid of the darn yellow streak altogther.

Thanks for any help or ideas.
Mo

[redcow]

I had a similar problem about a year ago. When scanning to email the pages posted to Outlook all had faint yellow vertical lines. It drove me crazy until I gently ran my finger over the ADF glass. I felt some bumps on the glass. Now this was after scrubbing the glass with alcohol and 'simple green'. I got a razor blade and scraped the glass smooth. The lines were gone.