Hello Nick,
I am not familiar with this specific device, however, I checked the user manual HERE and it does not list the Corotron Wire as a Customer Replaceable item. This may need a service call.
I Have a C1190 FS colour Laser printer and the black prints in gray. The other colours work fine. It has been suggested in Whirlpool to clean the Corona wire or replace the ink. I replaced the ink to no avail, however, I don't know where the corona wire is.