So I have a Dell 3130n where the black toner cartridge is possibly leaking. The drum gets the 2 streaks at the margin, which is pretty common (we have several such printers at the office). However, this is the first time that wiping the drum off with a microfibre cloth has not improved the situation, usually I can turn through the whole thing, wiping as I turn, and when I get to where I started it is all clean with no new spillage. However I just turn and turn infinitely and there is always more on the drum. I am assuming that it is leaking, is there any way I can confirm this and possibly fix it? The toner was changed v recently and I'd rather not have to replace it.
I've noticed this happening with defective toner cartridges in the past. If you have another toner of the same model, try swapping it out. This usually fixes the problem of excessive toner dump for me.