Chapter 7---Troubleshooting7-12 Model 250 Service Manual7.3 DiagramsCommand ON TimingFigure 7-10 POWER ON and POWER OFF command timing diagram.When the AC Circuit Breaker is powered ON, the Low Voltage Power Supplygenerates a +5.1 V Standby voltage that goes to the System Controller PCB topower the CPU and IR Detectors. The Low Voltage Power Supply also puts outthe +24 V Standby voltage (/FAN_ENA goes low) that provides power to thecooling fans. The cooling fans run from the time the AC Circuit Breaker ispowered ON until approximately ten minutes after the projector receives a powerOff command (AC Circuit Breaker still on).When the projector receives a power ON command from the IR Remote, PC orLaptop, the System Controller PCB receives a /LAMP_OK from the Arc LampPower Supply. The System Controller PCB then drives the /LAMP_ENA signal
