HP 8150dn Service Manual - Page 219

2 x 500-sheet Input Tray Operation Communication and control of the input device are made through the Paper Handling Controller by a sequence of instructions controlled into the 2 x 500-sheet Input Tray controller PCA. Pickup and Feed System When each tray in the 2 x 500-sheet Input Tray is loaded with paper and the paper tray is closed, the paper stack moves into position under the Pickup, Feed, and Separation Rollers. The trays are detected by the PS1202 sensor in the upper tray and by the PS1201 sensor in the lower tray. The presence of paper is detected in the upper paper tray by the PS1208 sensor, and in the lower tray by sensor PS1207. The paper level is detected by switches SW1205 and SW1206 in the upper tray, and by switches SW1203 and SW1204 in the lower tray. The paper size is detected by switches SW1601 through SW1604 installed in each tray. Table 5-7. 2 x 500-sheet Input Tray Switches Paper Size Ledger (Portrait) A3 (Portrait) B4 (Portrait Legal (Portrait) Letter (Landscape) A4 (Landscape) SW1601 OFF OFF ON ON OFF OFF SW1602 OFF ON OFF ON OFF OFF SW1603 OFF OFF OFF OFF OFF ON SW1604 OFF OFF OFF OFF ON OFF When the Paper Handling Controller in the printer sends an input command to the Controller PCA on the 2 x 500-sheet Input Tray, the 2 x 500-sheet Input Tray driver engages the Pickup Motor to rotate the Pickup, Feed, and Separation Rollers. The direction of rotation of the Pickup motor determines which set of rollers are activated. When the motor rotates clockwise, the paper is picked up from the upper tray, and when the motor rotates counterclockwise, the paper is picked up from the lower tray.The 2 x 500-sheet Input Tray driver also engages the 2 x 500-sheet Input Tray motor to activate the Pickup Solenoid, which lowers the rollers to the level of the paper. As the Pickup Roller turns, the paper feeds into the Vertical Transfer Unit (VTU) and passes through the PS1 and PS2 sensors. 214 Chapter 5 Functional OverviewC4265-90907