| It's the receiving tray, pull it off, there are two sensors over the revolver unit. One towards the middle is the density sensor. You can open it manually and blow it out with air. One towards rear of machine is toner detection, blow it off with air. (You'll have to remove them, a few screws) to clean them well.
You will have to pull finisher and bridge off if the machine has one, two screws for recv. tray. |