How do I clean under the scanner head or glass? I get dust on scanned color photos at 300dpi and the glass is totally clean.

I recommend you do not take off the glass. I have done it and was never able to get rid of the dust, which really shows up on every scan. The fogging has something to do with an optical coating on the underside of the glass. If I knew then what I know now, I would let it be. If the fogging doesn't show up in scans, leave it. If it really does show up, the glass itself is often held down by simple double stick tape. You try to keep the tape intact so you can put it back down. It may be strong enough that the plastic frame on top of it could snap. Do it in as clean (not dusty) environment as possible so dust does not drift down inside the scanner. Never touch the lamp or move the scan mechanism. Again, don't do it unless it's showing up on scan results. Sadly, nobody "fixes" scanners, they are disposable, like coffee pots, even if they cost 300.00.

clean the scanner glass and scanner mirrors might be dust on the scanner

I have the same problem. Can't get any help from HP.

If the lines are in the same location for all scanned outputs, it is clearly dust on the scanner glass. Clean it thoroughly.
S. Mohan, India

please diagnose to realigning your ink cartridge...

you should try to clean the glass on your scanner.or clean the printer ink heads.

You can clean the scanner glass with warm water and a dust free cloth. Is the line always in the same spot in your scans? Could be something else other then dirty glass.

There's probably nothing you can do for dust under the glass, but in the Advanced settings for your scanner, there is an option to turn on "Reduce Dust & Scratches", with three different 'strengths'. You may want to try this to see if it helps.

when poering on this HP 2840 it says" Scanner Error 5"
what does it mean? How to get a solution?

Hi, perhaps the Platter Glass is dirty or dust has gotten into the base and onto the scanning head... try giving it a good clean, I use compressed air cans, when in the field and nitrogen at the Lab, and blow the dust and dirt away.. Use a good quality Glass Cleaner OR Methylated Spirits on the Glass, NOT the Scan Head tho.. Just Blast that with the "Canned Air".. I have even used a Vacuum cleaner set to "Blow" in a pinch..