Dark streak down middle of the page

[HWonders]

Getting a black streak down middle of the page. Changed toner cartridges. Checked for a peice of paper or something iside and in the back. Multiple cleaning pages. Seems to be getting worse. Can't find an issue. Short of dismantleing,  it not sure what to do next?

[Valsimot]

Looks looks transfer belt isn't cleaned good. There is a rubber blade inside the belt that cleans the surface of the belt and you might have something on the blade that is causing the line.

[HWonders]

I looked at the belt and didn't see anything. It looked clean. I know you're not supposed to touch it. How to you access the "rubber blade"? From the back somehow? I see no way I can reach into the printer without touching the belt. 

It would be like that old Operation game. My luck I'd ruin it.

[Valsimot]

It needs to be removed and disassembled and cleaned. Messy job. Are you using original on refilled toners?

[HWonders]

Original, although I tried refilled ones once early on and stopped.  Lousy color and premature failures.  This just started happening last week.  Worked flawlessly up to now.

I'll see if there's a video online detailing cleaning it. Might as well try it before I buy another.

Thanks for the help.