Turn off the printer but keep it plugged into power and connected to your PC via USB. Stop/Reset button, then press and hold the While holding Power, release Stop/Reset, then press it (the LED will alternate between green and orange).
Think of this tool as the "skeleton key" for your printer. Most users turn to it for one primary reason: (the "Pampers" reset). When the printer thinks its internal pads are soaked with ink, it locks itself to prevent leaks. The v3600 tool tells the printer's brain that the pads have been "cleaned" (though you should physically check them too!). How to Use It (The "Secret Handshake") Canon service tool v3600
The printer must be manually placed into "Service Mode" (usually by a specific sequence of the Power and Stop/Reset buttons) before the software will recognize it. USB Connection: Turn off the printer but keep it plugged