HP 3030 Service Manual - Page 98

Printer laser/scanner unit The ECU sends signals to the laser/scanner assembly to modulate the laser-diode on and off modes and to drive the laser/scanner motor. VDO /VDO /BDI CNT0 CNT1 /BD Laser driver PCB Cylindrical lens BD sensor /ACC /DEC Photosensitive drum Figure 4-4. Formatter Engine controller PCB Laser/scanner operation Four-sided mirror Scanner motor Focusing lens Power system on the power-supply assembly The ac, dc, and high-voltage power supply circuits are all provided by the power-supply assembly. Ac power distribution The ac power circuitry supplies ac voltage whenever the power cord is connected to the ac power source and the power switch is on. The ac voltage is distributed to the dc power supply circuitry and to the ac driver circuitry, which controls ac voltage to the fuser assembly heating element. Dc power distribution The dc power distribution circuitry, located on the engine power assembly, distributes +3.3 Vdc, +5 Vdc, and +24 Vdc as follows: Table 4-5. Dc power distribution +3.3 Vdc +5 Vdc ECU, sensors, formatter Parallel interface on the 1015 formatter 80 Chapter 4 Operational overview ENWW