Press and hold the button (the triangle inside a circle).
Step-by-Step Instructions: Resetting Canon 5B00 Error (v3600) Canon service tool v3600
If you have multiple printers connected to your PC, unplug them before running the Service Tool to avoid sending reset commands to the wrong machine. Press and hold the button (the triangle inside a circle)
Performs a deep cleaning of the print head mechanisms. Supported Printers for v3600 Canon service tool v3600
Using service tools carries inherent risks. If used incorrectly, you can "brick" the printer’s logic board, rendering it permanently unusable. Always ensure you are using a version of the software that is compatible with your specific model.