HP 2300d Service Manual - Page 105

Sheet feeders HP LaserJet 2300 series printers can use two optional sheet feeders: the 250-sheet feeder and the 500-sheet feeder. The sheet feeders are driven by the printer and controlled by the printer's engine controller. The engine controller drives the solenoid at a necessary timing through the sheet feeder PCA. The paper sensor detects media. The sheet feeder picks up media loaded in the cassettes and transports it to the printer. The flow of media is illustrated in figure 33 (the 500-sheet paper feeder is shown). Figure 33. Pickup-feed paper path The main motor (M903) uses gears to drive the sheet feeder. When a print command is received from the formatter, the main motor (M903), reverse motor (M904), and scanner motor start rotating. The heating element temperature begins to rise. The sheet feeder pickup solenoids (SL2001, SL2002) are turned on when the following three requirements are met: q the main motor has been driven for 0.35 seconds q the scanner motor has reached the specified rotation number q the heating element temperature has been brought to the specified temperature, or the specified period of time has elapsed after start of the temperature control SL2001 and SL2002 transmit the main motor's rotation to the pickup roller. The pickup roller makes a rotation to pick up media in the cassette. The separation pad separates the media and transports it to the printer. The media goes through the transfer, separation, and fuser/delivery blocks, and is delivered to the selected tray. ENWW Chapter 5 Theory of operation 103