HP
LaserJet M428fdw
- Issue
- Scanner producing black lines across scanned documents. ADF feeding but scanner output corrupted.
- Solution
- Replaced cracked ADF scanner glass strip. Cleaned flatbed scanner glass and calibration strip. Tested scan-to-email and copy functions.
Technician's note
Hairline crack in CIS scanner glass invisible to naked eye but caused consistent vertical line artifact.
- HP
- MFP
- Scanner



