Hp Officejet Pro 7740 unable to scan certain colours

[Enamory]

Hello,
My brand new HP Officejet 7740 scanner doesn't seem to be scanning bright highlighter-type colours like greens, yellows and pinks. I tried scanning using both HP Smart and Image Capture on my computer with the same result. It's as if the sensors in the scanner cannot detect those colours.
The scanned images says they are RGB so the colours should be repeatable since neons are visible on screen. I was wondering if the problem was in the  printer/scanner software or if it actually scans in CMYK and converts (in which case neon colours wouldn't appear properly as neons cannot be printed using standard CMYK inks.) But when I took a photo of the image I was trying to scan and converted it to CMYK the colours appeared, although duller, the proper colour. The scanner seems to colour shift things to the blue side and is not very true to life. Here's an example of what I mean:

Colour comparison on artworkColour comparison on sample colours

You can see clearly that the scanner shifts yellow hues to the blue side to a point where yellow appears green and green is a teal/blue colour. For those of us (like myself) who are artists and use this to scan artwork this is a huge issue. Hopefully it can be resolved with an update to improve the way the sensors detect yellow-shifted colours, otherwise this scanner is pretty useless for artists.

[Jay_G24]

Hi @Enamory,

I understand you are facing scan quality issue, I'd like to help.

Let's try a power reset on the printer

Reset the product

• With the printer turned on, disconnect the power cord from the rear of the printer.
• Unplug the power cord from the wall outlet.
• Wait at least 60 seconds.
• Plug the power cord back into the wall outlet.
• Reconnect the power cord to the printer.
• Turn the printer on. HP recommends plugging the printer directly into a wall outlet.

Also, try updating the printer's firmware - HP Printers - Updating or Upgrading Printer Firmware 

Clean the scanner

Fingerprints, smudges, dust, or debris on the scanner glass, under the scanner lid, or in the document feed slot can cause lines and color bands. Clean these parts with a soft, lint-free cloth sprayed with glass cleaner.

Read one of the following sections for steps to clean these components, depending on your printer type.

Printer with flatbed scanner glass and lid

Printer with a document scan feeder

Printers with a flatbed scanner glass and lid

Clean the scanner glass and underside of the scanner lid with a soft, lint-free cloth sprayed with glass cleaner.

1. Turn the printer off, then disconnect the power cord.

2. Lift the scanner lid.

3. Spray a soft, lint-free cloth with glass cleaner, then wipe the scanner glass, glass strip (if present), the white backing under the scanner lid, and the white strip under the lid (if present) until clean, dry, and streak-free.

      CAUTION: 

   To protect the interior printer parts, do not spray the cleaner directly on the glass or on the underside of the lid.

   

4. Reconnect the power cord, turn on the printer, then close the scanner lid completely.

5. Load the original document or photo, then try to scan. Make sure the original document or photo is in good condition and free of tears, creases, folds, staples, or tape

Refer to -Improving Scan Quality

Hope this helps! Keep me posted. 

And, Welcome to the HP Support Community. 

Please click “Accept as 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

[Enamory]

Hello,

I've tried all of those suggestions and my scanner is still colour shifting bright yellows to green and greens to blue.

It seems I'm not the only one with this issue:

https://h30434.www3.hp.com/t5/Scanning-Faxing-and-Copying/HP-Office-Jet-Pro-7740-not-scanning-all-co...

https://h30434.www3.hp.com/t5/Inkjet-Printing/calibrate-colors-scanned-with-colors-printed-on-HP-774...

Some of those are 3 years old - has HP really not fixed this issue? I wish I'd known before buying!!

[Kumar0307]

@Enamory

Have you tried making a copy of a color document using the flatbed glass and the feeder to check if the issue persists? By this, we can conclude if this is a hardware or a driver issue.

If the copy quality is not satisfactory, this could be a hardware issue with the scanner mechanism in the printer.

Keep us posted.

[Enamory]

Hello,

Good suggestion. I just tried and what appears on the page is even worse than on the scan. Below is the result - to the left is the copy, to the right is the original. The yellow barely even shows up. I also printed a spectrum to see how the printer actually handles colours separately to the scanbed and it looks like it struggles with yellows in general. Anything not 100% yellow appears green.

To add, I printed the photo I took of the 3 colour stripes and it prints reasonably accurate. The yellows are very visible. So it seems like it has something to do with the scanner.

 

[Kumar0307]

@Enamory

This looks like a hardware issue with the scanner mechanism. Please reach out to the HP Support in your region regarding the service options for your printer. 

Keep me posted for any other assistance.