Differences in print engines The following are the parts differences between the HP LaserJet 9000 series printer and the HP LaserJet 9000mfp. Delivery tray Face-down tray fan Grounding cable Control panel cable Delivery unit (scanner) DC power supply DC controller (printer) (printer) DC power supply Power supply cable Figure 37. Differences in print engine 66 Chapter 5 Theory of operation C8523-90921