: The tool will not work unless your printer is first put into "Service Mode." How to Enter Service Mode

Canon generally recommends that these services be performed by official service centers to ensure the physical integrity of the device. asia.canon Conclusion

The printer's mainboard/EEPROM is locked. This happens if someone previously attempted to enter Service Mode using the wrong key combinations too many times. A locked EEPROM usually requires a physical chip replacement or physical desoldering. Important Safety Warning: Physical Maintenance Required

Press the Stop button exactly 5 times (6 times for select G-series models). Release Power: Release the Power button completely.