Don't print the black color
Doing reference on your issue. Double check the ink cartridge to make sure that the cartridge is correctly installed. Also be sure that the black ink cartridge used is compatible with the machine.
The next thing to do is a cartridge cleaning as the belief is that the print head is blocked. If you have done a thurough cleaning, the next thing to do is replace the black ink cartridge to be certain the ink cartridge is not faulty.
I have included print head cleaning instructions in case you have not done this cleaning process.
here is some information from the Brother support site:
If one or more of the ink colors are missing from pages printed by your machine (i.e. received faxes, copies and/or documents printed from the PC etc), nozzles in the print head may be clogged, or the ink cartridge in question may not be installed correctly. Verifying that the ink cartridges are installed correctly and/or cleaning the print head may solve the problem.
Cleaning the print head may solve the problem. When cleaning the print head, you are given the option to clean BLACK ONLY, one of the three colors (CYAN, YELLOW, or MAGENTA), or all four colors at once. For this issue we recommend cleaning only the affected color. If more than one color is missing then choose ALL.
When the machine completes cleaning the print head, press Color Start. A Print Quality Check Sheet will print.
I did what you said and it did not work. Did you try replacing the Print head?