If you have a lack of one (0r more) color do the following:
- Make sure all carts are full, placed well and are secured.
- Insert a new original brother cartridge for the one that shows no color.
- Press menu then start bk-copy
- Press four times arrow up quick after another
- The printer will switch into maintenance mode and all lights will flash.
- Press 7 then 6 then 4 then start bk-copy.
- The printer will initialize the cartridges and refresh ink within tubes and print head. After that it does some power cleaning.
- When finished press 7 then 6 then 3 then start bk-copy. The printer will run a power purge.
- When finished press 9 then 9 to leave the maintenance mode. do run a quality test print.
Repeat until desired results.
Newer printers can use the following guide to access the maintenance menu: http://www.refreshcartridges.co.uk/igloo/how-to-the-reset-purge-counter-on-a-brother-printer-with-a-numerical-pad/