- HP Laserjet Enterprise CP4020/CP4520 Manual

SR5 Tray 4 paper surface sensor 1 (3 x 500-sheet paper feeder only)
SR6 Tray 4 paper surface sensor 2 (3 x 500-sheet paper feeder only)
SR7 Tray 4 feed sensor (3 x 500-sheet paper feeder only)
SR8 Tray 4 media-stack-surface sensor (3 x 500-sheet paper feeder only)
SR9 Tray 5 paper surface sensor 1 (3 x 500-sheet paper feeder only)
SR10 Tray 5 feed sensor (3 x 500-sheet paper feeder only)
SR11 Tray 5 paper present sensor (3 x 500-sheet paper feeder only)
SR12 Tray 5 media-stack-surface sensor (3 x 500-sheet paper feeder only)
SW1 Tray 3, 4, and 5 right door switch
SW2 Tray 3 paper size switches (3 x 500-sheet paper feeder only)
SW3 Tray 4 paper size switches (3 x 500-sheet paper feeder only)
SW4 Tray 5 paper size switches (3 x 500-sheet paper feeder only)
Paper-size detection and cassette-presence detection
The paper feeder detects the size of paper loaded in the paper feeder and the presence of the cassette
using the PD media size switch.
Paper size Paper-feeder cassette media-size switch settings
Top switch
Center switch Bottom switch
Universal ON ON ON
A5 OFF OFF ON
B5 OFF ON ON
Executive ON OFF ON
Letter OFF ON OFF
A4 ON OFF OFF
Legal ON ON OFF
No cassette OFF OFF OFF
62 Chapter 1 Theory of operation ENWW