When I scan with envy 7640 document feeder there is a faint smudge at bottom left of scan

[kwy430]

I have a HP Envy 7640 printer. Scans of documents using the auto document feeder started to have streaks down the length of the page. I cleaned the glass where scanning takes place and that eliminated the streaks. However, there were some smudges. I saw that the path from where pages are loaded into the scan mechanism was dusty so I wiped the interior with a wet cloth. I only got some of the dust so I sprayed compressed air into the opening and then from the bottom after I lifted the lid. Now the scanned documents are clean except for a light smudge that half inch wide by inch long at the bottom left. I can't take the document feeder apart apparently. What can I do? Thanks! 

[Max3Aj · Accepted solution]

@kwy430, Welcome to HP Support Community. 

Thank you for posting your query, I will be glad to help you. 
If you're experiencing a faint smudge at the bottom left of your scans when using the document feeder on your HP printer, it’s likely due to dirt, dust, or residue on the scanner glass or the white background strip inside the ADF (Automatic Document Feeder). Here are the steps you can take to resolve the issue:

Steps to Fix the Smudge in ADF Scans

Clean the ADF Scanner Glass Thoroughly

• Locate the ADF Glass: Open the scanner lid and look for a thin strip of glass next to the main scanning bed. This narrow strip is used for ADF scanning.
• Wipe the Glass: Use a lint-free cloth dampened with glass cleaner or isopropyl alcohol (avoid spraying directly onto the glass) to clean the strip.
• Inspect for Smudges: Check for any tiny smudges, ink marks, or adhesive residue and clean them off.

Inspect and Clean the White Background Strip

• Access the ADF Lid: Lift the ADF lid (if accessible) and look at the white background strip, usually located on the underside of the ADF lid.
• Clean the Strip: If it’s dirty or stained, gently clean it with a soft cloth. If it appears damaged or discolored, it may need replacing.

Manually Feed a Cleaning Sheet

• Prepare a Cleaning Sheet: Take a clean, lint-free sheet of paper and lightly dampen it with water or a mild cleaning solution.
• Load and Scan: Load it into the document feeder and scan it to help clean any remaining dust inside the mechanism. If available, consider using an ADF cleaning sheet (commercially available).

Check for Residue on ADF Rollers

• Inspect the Rollers: Open the ADF cover (if possible) and inspect the rollers.
• Clean the Rollers: Wipe them with a cloth dampened with water or isopropyl alcohol to remove any dust buildup. Allow them to dry completely before scanning again.

Try Scanning from the Flatbed Scanner

• Test the Flatbed: If the smudge does not appear when scanning from the flatbed, the issue is likely within the ADF.
• Check Software: If the smudge still appears, it could be a software issue—try scanning using Windows Fax and Scan or HP Smart to see if the problem persists.

Final Check

• Scan a Blank Sheet: After cleaning, scan a blank sheet of paper using the ADF and check if the smudge is gone.
• Reset the Printer: If the issue remains, try resetting the printer by unplugging it for a few minutes and then turning it back on.

I hope this helps. 

Take care and have a good day. 

Please click “Accepted Solution” if you feel my post solved your issue, it will help others find the solution. Click the “Kudos/Thumbs Up" on the bottom right to say “Thanks” for helping! 

Max3Aj

HP Support 

[kwy430]

Hi Max3Aj, Thanks so much. I will accept your detailed, lengthy solution.

If I scan using a single sheet on the flat bed glass, the scan does not have smudges. It is the ADF for certain. I have cleaned all the glass I can reach as well as rollers. I will clean those again. I will try the paper made for cleaning the ADF. This printer is at least a few years old and has some dust in the cavity on the ADF top (paper is fed into that cavity). I will try to clean that with a cloth or a very long Q-Tip.

Thanks again!

Regards,

Bill