Canon iR8500 Service Manual page 792

E420
(iR7200)
Main cause The EEPROM is faulty. The ADF controller PCB is faulty.
Condition
0001 When the host machine's power switch is turned on, the backup
E421
(Indicated if iR7200)
Main Cause The EEPROM is faulty. The ADF controller PCB is faulty.
Condition
0001 Backup data cannot be written to the EEPROM or the data, if writ-
E422
(Indicated if iR7200)
Main Cause The IPC communication has an error. The communication line has an open
circuit. The ADF controller PCB is faulty.
Condition
0001 While the machine is in standby, the communication with the host
COPYRIGHT© 2001 CANON INC.
data of the EEPROM cannot be read or the data, if read, has an er-
ror.
ten, has an error.
machine has been interrupted for 5 secs or more. or, while the ma-
chine is in operation, the communication with the host machine has
been interrupted for 0.5 sec or more.
2000 2000 2000 2000 CANON iR8500/7200 REV.1 AUG. 2001
ERROR CODE
E-17