C. Detecting Errors in the Power Supply PCBThe microprocessor (Q512) on the composite power supply PCB either displays anerror message on the display by communicating with the DC controller or flashesLED501 to indicate the presence of an error if any of the following is identified.1. Communication Error between DC Controller PCB and Composite PowerSupply PCBIf an error occurs in the communication between the DC controller PCB and thecomposite power supply PCB, E240 is indicated as soon as it is detected by themicroprocessor on the DC controller PCB. If an error is detected by the composite powersupply, the LED is flashed at intervals of 5 sec.2. Error in the High-Voltage Output DataIf the difference between the setting associated with the high voltage generated bythe microprocessor (Q512) on the composite power supply PCB and the control value isgreater than the specified value, the microprocessor (Q512) sends error data to the DCcontroller PCB, which in turn indicates E064.3. Low-Voltage Output Data ErrorIf the difference between the setting associated with the low voltage generated by themicroprocessor (Q512) on the composite power supply PCB and the control value isgreater than the specified value, the microprocessor (Q512) communicates with the DCcontroller PCB, which in turn indicates E803.4. Overcurrent in the Low-voltage Power SupplyIf the composite power supply PCB identifies overcurrent because of an error in a DCload or wire is trapped, the LED is flashed at intervals of 2 sec for 20 sec.Reference:Normally, the LED is flashing at intervals of 0.5 sec.COPYRIGHT © 1997 CANON INC. CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)7-4CHAPTER 7 EXTERNALS/AUXILIARY MECHANISMS
