: The printer must be put into a special "Download Mode" by holding specific buttons (usually Stop/Clear ) during startup. Installation

: Connect the printer via USB cable (not Wi-Fi). Ensure you have the printer's Serial Number, firmware version, and CRUM number, as many fixes are unique to specific machines. Enter Download Mode : Turn off the printer. Hold the Stop button while pressing Power .

If your version is , you are locked down. You need to downgrade to V2.xx.xx.xx or use a special service firmware.

If you absolutely must use the firmware fix:

The keyword phrase "firmware fix" refers to modifying or downgrading the printer’s internal software to ignore these toner checks.