HP M3027 Service Manual - Page 72

Engine control unit (ECU) The ECU coordinates all device functions, according to commands that the formatter sends. It drives the laser/scanner system, the image formation system, and the pickup/feed/delivery system. The ECU contains the following components: ● Engine-controller PCA ● Low-voltage PCA Figure 4-5 Print engine general structure on page 60 shows the relationship of the ECU to the pickup/ feed/delivery system, the laser/scanner system, and the image-formation system. Figure 4-6 Engine control unit circuit diagram on page 61 provides the ECU circuit diagram. Figure 4-7 LVPS circuit diagram on page 61 shows the low-voltage power supply circuit on the ECU. Rear output bin Output bin LASER/SCANNER SYSTEM Scanning mirror Laser diode BD circuit Scanner motor IMAGE Primary charging FORMATION roller SYSTEM Developing unit Fuser PhotoCleaning unit sensitive drum Transfer charging roller Duplex feed unit Tray 2 Tray 2 pickup unit ECU Engine controller PCA High-voltage Power supply PCA Formatter Option Tray 1 Tray 1 pickup unit PICKUP / FEED SYSTEM Figure 4-5 Print engine general structure 60 Chapter 4 Theory of operation ENWW