Dark or black copy

Make multiple copies of Jet black print for example, open the platen cover and then make blank copies.Print out will be jet black.After about 60 to 70 copies background will be adjusted, if not then replace the toner.After replacing the toner if the background is still there then you must replace the developer.

1st the basic cause of dark/grey copies DUST. Clean w/ alcohol cloth then dry cloth totally all mirrors and the platen glass both side. If still dark check the "Optic slit " right in the upper of your halogen lamp remove it, still dark Check your halogen lamp maybe it already oxidized. The last solution adjust the CVR .

The cartridge or Toner is splitting out more ink.... Remove the cartridge Clean it and place it again.

Whenever you ask about any problem please explain in detail.There are couple of reasons behind the above mentioned problem.Its not clear that copies are all black (full black) or just dark in print density? or its giving a dark shade? As per asked question, the solution is Check the followings1-Scanner mirrors are dirty2-Drum is damaged or faulty3-Charging corona 4-LD unit5-Developer

dark copies you mean there is a dark background but image is still there?
it is usually happens when all mirrors and **** glass becomes dirty. you should clean it
well if you mean an image with pure black copy output, probably your exposure lamp is busted or the thermostat is open. :)

Hello sir; That problem not caused by toner, is by drum cartridge, replace it will take care your problem.

just service copier properly specially optics or check parts life

is there toner in the machine ? ( toner spill)
check the manual for the location of the glass, in the maintenance section, if it has toner on it copies will be black or dark, other wise the scaning glass is bad

http://www.retrevo.com/s/canon+7000+manual

How long has the drum been in there?
try this:
1-take out toner, look and see if it is ok. do you see stripes on it?
2- look at the drum are there any black rings on it? ( you did not specify white or black lines)
3- where the glass is on the opposite side ( the part you lifted to clean the glass, look at it standing from the back. you will see a white metal plate with some springs in it if you touch it. this is the reference that the fax has if there is/are a black dot on it it will give you a black line clean carefully. if it is scratched use white out to cover and make white again.

For the darkness try making a copy in photo mode if it is still too dark change drum.

Dark shades on both side of the paper? Drum cleaning blade or fuser assembly. Check the upper fuser roller and the drum for build up.