There is a line down the middle of all pages when copying. The quality of the copy is fine otherwise.

Open flat bed, remove scan camera, clean internal reflector glasses with ear buds to clean dust on it, as well as clean flat bed glass with galss cleaner both sides fix it back, check copy & scan...

your printer drum is worn out.
try to clean it with tissue paper gently if it work its fine
otherwise you have to replace the drum

I am assuming that you are talking about scaning or copying somethign when you mention glass. The line can be from memory or a driver, Try setting the scan quality down to see if it goes away.

you can downlaod the driver form this link
http://h20000.www2.hp.com/bizsupport/TechSupport/DriverDownload.jsp?prodNameId=390320&lang=en&cc=us&taskId=135&prodSeriesId=390314&prodTypeId=18972

check if there is any kind of leank inside the printer. do a manual servicing once.

Morgansaki,

You have a dirty scanner lense. when you lift the top cover, as though you were going to do a copy from the platten glass, you will see there is a smaller glass to the left hand side of the scanner. look very hard at this glass and you will see there is a dirty mark on the lense. clean the cglass thoroughly with some quality window cleaner and you will find you line will go away.

Gremlin11

this should solve your issue with detailed explanation!
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c01129408&cc=us&lc=en&dlc=en&product=3301296#

If you make a copy, does the copy have dark areas down the middle of the page? If so, remove the toner cartridge and gently roll it around to redistribute the toner inside, maybe even replace the toner cartridge if you've had it a long while. If you still see unevenness, you may need to have the machine looked at.

If the copies you make on your machine look fine, then I would suspect that the person sending you the fax has a dirty scanning element. Check with them to see if they can clean the scanning element and it should improve the fax quality.

Can't image it being anything but scan glass, if prints are fine, are you sure you cleaning scan glass(inside of where originals are fed)?

If so then scanner lamp faulty, but I've never come across it myself on this model.