Oki c5150 wont print black
First, clean the LED heads with a lint free cloth and isopropyl alcohol (the LED heads are the attachments on the underside of the lid when you open your printer; four of them for each color). Try printing something after doing that. If it's still an issue just with black, try switching the black and magenta drums/toner (keeping them locked together). The drum w/ toner cartridge simply pulls straight up and out, no switches or locks to flip. Then print a page of text; which will output from the printer in magenta. If that looks okay, then it may be an issue with your black drum and needs to be replaced.