Start with the obvious. Remove the "Y" toner cartridge, inspect it and the carrier for problems. You can use canned air or vacuum to clean things up if needed. Try replacing the cartridge, does the problem follow? Now you have ruled out the cartridge itself or issue with the printer.
~Rick
Bay Area - CA
~R5 C (1.1.2.1), ~R50v (1.1.1) ~RF Trinity, ~RF 100 Macro, ~RF 100~400, ~RF 100~500, ~RF 200-800 +RF 1.4x TC, BG-R10, 430EX III-RT ~DxO PhotoLab Elite ~DaVinci Resolve Studio ~ImageClass MF644Cdw/MF656Cdw ~Pixel 10 ~CarePaks Are Worth It
