The tool will not work unless the printer is in Service Mode. Follow these steps carefully: Power Off: Ensure the printer is off but plugged in. Press & Hold: button (red triangle), then press and hold the Release & Tap:
Please let me know if you want me to make any changes. Canon Service Tool V.3900 Download
To use Version 3900, the printer must first be placed into manually: The tool will not work unless the printer is in Service Mode
: The tool’s most common use is resetting the waste ink counter to 0%, allowing the printer to bypass internal blocks that stop it from printing when it "thinks" the absorbers are full. Canon Service Tool V.3900 Download