Brother 1440 Printer Black streak - is it Drum or Toner?

On my black and white toner printer I wiped the drum off with a rag and it solved the problem.

sounds like a possible problem with possibly the drum or the transfer belt. trying a different toner cartridge may fix the problem but it may not. Most likely given the cost of repair, replacement may be your best option.
thank you,
Lee

The printer drum (photoconductor) is part of the toner unit.
There is a button on the left side of the printer.
Push the button. The front will open up.
The drum unit and toner can be pulled out.
Remove the toner unit from the drum.
Install the toner unit into the new drum unit.
push the whole unit back into the printer.

The first thing I would try is to fix the corona wire. Here is a link to Brother's website outlining the process (clean corona wire).
What you need to do is pull out the drum and look for a blue tab on the top of the cartridge. Slide that tab back and forth along the wire and see if that clears things up.
I have had some luck cleaning the drum when I get black streaks but I have also hear this can be dangerous and make the problem worse.
http://welcome.solutions.brother.com/BSC/public/us/ca/en/faq/faq/000000/000200/000008/faq000208_022.html?reg=us&c=ca&lang=en&prod=mfc7340_us_as&Cat=7

If you have a old drum or old toner cartridge switch them and see if it goes away. Other wise start with a new toner cartridge. I sell them for 40.00 and the drum for 60.00. Steven 818-888-0006

Pull out the Toner Cartridge and clean its drum with a Soft Lint Free cloth. Hope your problem will be solved.

may some dust in corona ware or drum clean the drum.

check your drum may the corona ware is broken . change the drum.

Seems like the drum needs changing. This is the most common cause for print problems in these printers. If using the high yield TN 6600 toner then you need to change the drum every 3-4 toners. If using the low yield TN 6300 toner then the drum will need replacing every 6-7 toners. Hope this helps

It sounds like excess toner has built up in or around the imaging drum. I would *carefully* remove the toner and drum (can be messy) and use some canned air to clean the inside out. If you are still getting these streaks, it might be time to get a new drum (DR 400) as you are supposed to replace the drum every 6 to 8 times you change the toner cartridge.