HP 4550 Service Manual - Page 131

Table 5-7 Motors, solenoids, and sensors Reference Description M3101 Duplex feed motor M3102 Reversing motor M3103 Side registration motor SL3101 Duplex feed roller pressure release solenoid SL3102 Delivery deflector solenoid PS3101 Reversing unit paper sensor PS3102 Face-up sensor PS3103 Reversing unit stationary paper sensor PS3104 Duplex pick-up paper sensor PS3105 Side registration home position sensor Reversing operation The media is guided to the duplex unit with the face-up deflector in conjunction with the face-up tray. If the face-up tray is closed, the delivery deflector solenoid (SL3102) operates the deflector. The duplex driver PCB turns the delivery deflector solenoid (SL3102). The rotation of the delivery deflector solenoid moves the delivery deflector, feeding the media into the duplexer. The reversing motor (M3102) rotates counter clockwise to feed the media into the reversing unit. Once the reversed paper sensor (PS3101) detects the trailing edge of the paper fed into the reversed unit, the duplex driver PCB changes the paper feed direction by rotating the reversing motor clockwise. Paper is then fed along the lower duplex guide until the paper reaches the duplex feed unit. Figure 5-33 Reversing operation C7085-90921 Chapter 5 Theory of operation 129