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What This Error Means

Canon Error 79 indicates a critical internal communication or firmware problem, often pointing to a malfunction with the printer's main control board.

Detailed Explanation

Error code 79 on Canon printers is a serious 'service call' error, signifying a fundamental issue within the printer's core electronics or its operating software (firmware). Unlike simpler errors like paper jams, this code suggests that the printer's main control board, which orchestrates all printer functions, is either failing, has corrupted firmware, or is experiencing a severe communication breakdown with other critical components. It essentially means the printer's 'brain' is not functioning correctly or cannot properly communicate with its 'body'. Common triggers for this error include sudden power surges or outages during operation, failed firmware updates, or simply the natural degradation or failure of electronic components on the main board over time. While less common, sometimes a faulty accessory (like a network card or an internal hard drive) connected to the main board can also cause this communication failure. The printer will typically become unresponsive or refuse to print, displaying the error prominently on its control panel.

DIY Troubleshooting Steps

Try these steps before calling a specialist

1
Perform a hard reset: Turn off the printer, unplug it from the wall outlet for at least 5 minutes, then plug it back in and turn it on.
2
Update firmware (if accessible): If the printer allows access to its menu or a utility software on your computer, check for and install the latest firmware update. Ensure a stable power supply during this process.
3
Remove all accessories: Disconnect any optional accessories like external network cards, additional paper trays, or USB devices, then restart the printer.
4
Check for internal obstructions (carefully): While unlikely to be the primary cause for Error 79, sometimes a foreign object interfering with a sensor can indirectly contribute to communication issues. Power off and unplug the printer, then carefully inspect accessible areas for debris.
5
Perform a factory reset (as a last resort): Consult your printer's manual for instructions on how to perform a factory reset. Be aware this will erase all custom settings and network configurations.

When to Call a Specialist

If the DIY steps, particularly the hard reset and firmware update (if possible), do not resolve the Error 79, it's highly indicative of a hardware failure, most likely the main control board. This component is complex and costly to replace, requiring specialized tools and expertise to diagnose and install. Attempting to replace it yourself without proper knowledge can cause further damage. A professional technician will have the diagnostic tools to confirm if the main board is indeed faulty or if another internal component is causing the communication breakdown.

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CANON Error Code 79