HP 4600 Service Manual - Page 187

Pickup and feed system The following is the sequence of operations for the 2 x 500-sheet paper feeder (the sequence of operation is the same for either cassette). Figure 5-42 2 x 500-sheet feeder pickup and feed operation illustrates this sequence. 1 The DC controller receives a print command from the formatter and sends a pickup command to the paper feeder driver. 2 The paper feeder driver rotates the main motor (M1) in the paper feeder, and the feed roller starts to rotate. 3 After the printer enters the SCANNER READY state, the DC controller instructs the paper feeder driver to pick a sheet of paper. The paper feeder pickup solenoid (SL1 for tray 3; SL2 for tray 4) turns on. The pickup roller makes one rotation and picks up paper in the cassette. 4 Separation pads eliminate any extra sheets, and a single piece of paper enters the feed path. HCI driver PCA LOWER CASSETTE PAPER SIZE DETECTION SIGNAL UPPER CASSETTE PAPER SIZE DETECTION SIGNAL MAIN MOTOR CONTROL SIGNAL LOWER CASSETTE PICKUP SOLENOID DRIVE SIGNAL (SLL) LOWER CASSETTE PAPER DETECTION SIGNAL (PS_L) UPPER CASSETTE PICKUP SOLENOID DRIVE SIGNAL (SLU) UPPER CASSETTE PAPER DETECTION SIGNAL (PS_U) FEED PAPER DETECTION SIGNAL (FS_1) SW1 SL1 SW2 SL2 M1 Figure 5-42 2 x 500-sheet feeder pickup and feed operation ENWW 2 x 500-sheet feeder 171