Ensure your printer is strictly in Service Mode (solid green light). Try switching to a different USB port on your PC, preferably a USB 2.0 port rather than a USB 3.0 port. Error Code 002
If you need help troubleshooting a specific error code, let me know the you are using and what LED light blinking sequence you see. I can provide the exact step-by-step instructions or recommend a different version of the Service Tool if V 3800 isn't compatible. Canon Service Tool V 3800 Download
Downloading and installing Canon Service Tool V 3800 is a straightforward process. Here is a step-by-step guide: Ensure your printer is strictly in Service Mode
echoed through the room. The LCD cleared. The error was gone. The machine hummed a low, satisfied note, and a single sheet of paper fed through, bearing nothing but the words: "Counter Reset: 0.00%." I can provide the exact step-by-step instructions or