Lexmark T520 Service Manual - Page 92

4520-xxx Tray X Low message displays when Tray X is full or has adequate paper in the tray. FRU 1 Paper Low Sensor Assembly Paper Low Sensor Flag Tray X Option System Board Action Run the Tray X Sensor Test and check the sensor for proper operation. If incorrect, check the following: Paper low sensor flag for smooth and correct operation. Paper low sensor for correct installation on the autocompensator housing. Paper low sensor cable for signs of cuts, pinched wiring or other damage especially at connector J5 on the system board. If no problem is found, replace the paper low sensor assembly. If this does not correct the problem, replace the option system board. Tray X Empty message displays when Tray X has paper in the tray. FRU 1 Paper Out Sensor Flag 2 Paper Out Sensor (On Option System Board) Action Check the paper out sensor flag for correct operation and installation. If correct, replace the option system board. (The paper out sensor is mounted on the system board). 2-64 Service Manual