Prints a strip of black down middle of page

Since you have Cyan toner in places where it should not be then the only possible cause is a defective Cyan Toner cartridge. I worked on one just last week where the customer complained about Magenta toner on their prints. I also noticed Magenta toner on the Transfer Belt just as you see Cyan toner on the Transfer Belt. I replaced the Magenta Toner Cartridge and everything cleared up nicely. The Transfer Belt Unit can also cause similar problems but it would not be ONLY one color like Cyan. It would be a mixture of all colors. My bet is replace the Cyan toner and you will be fine. If you have an old empty one just shake it up a bit and try it as well. This might allow you to verify before buying a new cartridge.
Good Luck and Thank You for using Fixya.
Wheatland Services

In my experience, the fuser has always been the cause of the lines.

The drum is defective, and leaking, Brother warranties if you are original purchaser (in canada, www.brother.ca)

The narrow pink line is coming from your magenta toner/drum cartridge. You may be able to open the from cover and look at the 4 toners. If you look at the magenta (like pink) cartridge, you might see the thin line on the drum surface.
The multicolored band that sometimes shows up on your prints is most likely the transfer belt unit. This is caused by an area of the belt that is not being cleaned very well. This probably tends to show up when you are running mutilple prints of a page.
So it looks like to may need to replace your magenta toner and look at getting a transfer belt unit.

you need to replace the K pcu and if the unit has 60K prints all of the consumables need replacing CMYK drums CMYK Developers and the imaging transfer belt and fuser unit

You need to clean the rollers.

You either have a defective black toner, a bad fuser or transfer belt. From my experence it is usually a bad toner cartridge. After you print a couple of pages, pull the black toner and see if there is anything on the drum. If there is try shaking the toner, sometimes toner does like dirt and clogs up. If you still have problem you will have to try another toner. I know that is not cheep, but I don't know any other way.

Samsung CLP-300 color laser leaves 3-4 lines of various shades of black in middle of paper. Otherwise everything is great.
Posssible black toner cartridge problem?

Most of the time when I find this happening on a printer, not just Ricoh's it turns out to be the PCU (photo conductor unit). The color PCU is one unit and the black is a seperate unit. Hope this helps.

I have the same problem. Any solution?