I have a Brother MVC 215C color inkjet with scanner, fax etc ...

If I don't print for a week or two, I have to clean the black ink - not the colors as they are fine, just the black. I've tried different cartridges with the same results. I have two original cartridges from Brother and they have been refilled as have the colors.

I'm on the same cartridges I bought with the printer two years ago.

Is it the print head?

Best would be check wether the black one's are original..cant be print head as u say the color catrg is fine.

Issue would be check the black catrg

All original cartridges. I have refilled them all at least twice. I have two blacks and the printer does the same thing. If I clean the black ink it works fine until I let it rest a few days then only the black gets spotty.

so your refilling? it might just be that the black ink you using is a little less then OEM quality. Try a new Brother cartridge (not a refill) and see if you get the same results after a few weeks of non use, all inks are not the same.