Paper Size Detection Switches Figure 7-21 Paper Size Detection Switches (1 of 3), Tray 2 (HP LaserJet 4000/4000 N and 4050/4050 N) Tray 3 Switches Tray 2 Switches Top Figure 7-22 Paper Size Detection Switches (2 of 3), Trays 2 and 3 (HP LaserJet 4000 T/4000 TN and 4050 T/4050 TN) 7-94 Troubleshooting