Canon Service Tool V.3900 Download |verified|

To use the Service Tool successfully, your printer must be connected via a (Wi-Fi will not work) and booted into Service Mode . Follow these exact steps to avoid corrupting your printer's mainboard. Step 1: Put the Printer into Service Mode

Still holding the Power button, press the button 5 times (or 6 times depending on your exact model). The indicator light will alternate between green and orange with each press. Release the Power button.