my canon printer ts6420a is connected to wifi but my computer just says 'printer offline'

Diagnosis

The "Printer Offline" status on a Canon PIXMA TS6420a, despite the printer showing a solid Wi-Fi icon on its OLED screen, indicates a communication breakdown at the software layer. This is rarely a hardware failure; instead, it is typically caused by a "stale" IP address. Because most home routers assign dynamic IP addresses (DHCP), your printer may have been assigned a new internal IP (e.g., changing from 192.168.1.15 to 192.168.1.22), but your Windows or macOS print spooler is still trying to send data to the old, defunct address. Another common culprit is the Windows "Use Printer Offline" toggle, which can be triggered automatically if the computer experiences a momentary timeout during a print job. Once this toggle is flipped, Windows stops attempting to communicate with the printer entirely, regardless of whether the printer is back online. You can confirm this by trying to print from a mobile device via the Canon PRINT app; if the mobile app works but the PC doesn't, the issue is strictly localized to your computer's driver configuration.

How to Fix It

To resolve the communication break and force the computer to recognize the TS6420a, follow these precise steps:

1. On your Windows PC, click the Start menu and type "Printers & scanners," then press Enter.
2. Locate the Canon TS6400 series (the driver name for the TS6420a) and click on it.
3. Select Open print queue. This opens a small window showing all pending documents.
4. In the top menu bar of the queue window, click the Printer tab.
5. Look for the option Use Printer Offline. If there is a checkmark next to it, click it to uncheck it. The status should immediately change to "Ready" or "Online."
6. If it remains offline, restart the Print Spooler: Press Win + R, type services.msc, and hit Enter. Scroll down to Print Spooler, right-click it, and select Restart.
7. Close all windows and attempt to print a test page.

If That Didn't Work

• Assign a Static IP Address: Access the printer's Remote UI by typing the printer's IP address (found in the Network Settings on the printer screen) into a web browser. Navigate to Network Settings > IPv4 and change the IP assignment from "Auto/DHCP" to "Manual." Assign a high-range IP like 192.168.1.200 to prevent conflicts with other devices. This ensures the PC never "loses" the printer again.
• Update the Port Configuration: Go to Control Panel > Devices and Printers. Right-click your TS6420a and select Printer Properties. Go to the Ports tab and click Configure Port. If the IP address listed there does not match the current IP shown on the printer's LCD screen, manually update the IP address field to match.
• Disable Windows Managed Printer: Windows 10 and 11 often try to install a "Class Driver" via Windows Update that conflicts with the official Canon driver. Uninstall the printer from "Printers & scanners," then go to "Apps & Features" and remove any "Canon" software. Reinstall using the full driver package from the Canon support site rather than letting Windows "find" the printer automatically.
• Power Cycle the Network Chain: Turn off the printer, shut down your PC, and unplug your router for 30 seconds. Plug the router back in first and wait for the internet to fully restore. Then turn on the printer, and finally, boot the PC. This clears the ARP cache in the router and forces a fresh handshake between all three devices.

Heads Up

• Avoid "WPS" for Long-term Stability: While the WPS button is fast for setup, manually entering the Wi-Fi password via the printer's menu is more stable and less prone to disconnection.
• Sleep Mode Issues: The TS6420a has an aggressive power-saving mode. If you rarely print, the printer may enter a "Deep Sleep" that some older network cards fail to wake up. Ensure "Auto Power Off" is disabled in the printer's Setup menu.
• Firewall Interference: Third-party antivirus software (like McAfee or Norton) often flags printer communication as "unrecognized traffic." If the problem persists, add an exception for the Canon TS6400 series in your firewall settings.
• Ink Level Alerts: Be aware that some Canon models will report as "Offline" or "Error" to the PC if there is a critical ink depletion or a paper jam, even if the Wi-Fi connection is active. Always check the printer's physical LCD screen for error codes like "E03" or "P02."