Model# 1600n

When I use the ADF, my copies come out with a black line down the centre of them. It takes me ages to make multiple sets of copies using the glass feature. I need to have the option of using the ADF for multiple copies  :-(

I should add that I have thoroughly cleaned the glass, the magnifier (long narrow piece of glass) or whatever it is called, the rollers, and the small window under the rollers. I have cleaned all these surfaces several times since this started yesterday - to no avail  :-(