HP Color LaserJet 9500 Service Manual - Page 75

Electric circuitry A 16-bit microprocessor is installed on the finisher controller PCB to control the finisher operation sequence and the Jet-Link communication with the video controller PCB. The finisher controller PCB drives solenoids and motors in response to the commands that the video controller PCB sends through the Jet-Link communication line. The finisher controller PCB also reports information about sensors and switches to the video controller PCB through the JetLink communication line. The following are important functions of the IC chips that are installed on the finisher controller PCB: ● IC21 (CPU): controls the operation sequence ● IC25 (EEP-ROM): backs up the adjustment values ● IC23 (flash memory): stores sequence programs ● IC1/IC4 (communication IC): communicates with the printer Figure 35. Signal flow between the output device and the video controller ENWW Chapter 5 Theory of operation 73