I have a Brother laser printer HL 1030 and I use Windows XP. It has started printing with a black smudge all the way down the left hand side of the paper. Cleaning the drum has no effect - wipe off ink/powder but this has no effect. Tried new cartridge as this has solved problem in the past but this has no effect either.
Please help.
elgnarc :

Can you remove the drum from the printer and physically inspect the surface of the drum.

What I expect you to find would be a void in the drum's surface. Other possibilities would be a problem in the drum cleaning station. Usually this is a vinyl type of plastic that sits behind the drum and scrapes residual toner off drum after a print cycle.

You may be looking at a service call to repair the printer.