IR3300 random Toner Line on prints and copies

[cokwax]

See attached image. This isn't a line as such, since it is not running down the page. I can call them random Toner marks.
It may appear anywhere on the page and the length varries. Some pages may come out without the defect.
I have tried a different dev. cylinder, spacers, charger, drum, with no luck. Any other ideas guys?

[copier tech]

Re: IR3300 random Toner Line on prints and copies

That looks like a bad drum earth, you are not using genuine Canon parts? A new drum unit will fix it.