my phone and laptop can't find the tr8620a for airprint anymore, it just disappeared from the network.

Diagnosis

The disappearance of the Canon PIXMA TR8620a from AirPrint lists is typically caused by a "handshake" failure between the printer's internal network interface card (NIC) and your router's DHCP server. This often happens after a power surge, a router firmware update, or when the printer enters a deep sleep mode and fails to wake its wireless radio, causing the device to lose its assigned IP address. Because AirPrint relies on Bonjour (mDNS) to broadcast the printer's presence, any disruption in the local network's multicast traffic will make the printer invisible to iPhones, iPads, and Macs, even if the printer appears "on." To confirm this is a network dropout and not a hardware failure, check the Wi-Fi indicator lamp on the operation panel. If the lamp is completely dark, the wireless radio is disabled. If it is flashing orange, the printer has lost its connection to the access point. If it is solid blue but still not appearing on your devices, the printer is connected to the router, but the router is blocking the discovery packets required for AirPrint to function. This is common in "Guest Network" environments where AP Isolation is enabled, preventing devices from seeing each other.

How to Fix It

Follow these exact steps to re-establish the connection and force the printer to broadcast its AirPrint signal:

1. Power cycle the hardware: Turn off the TR8620a using the power button, then unplug the power cable from the wall. Unplug your wireless router for 30 seconds. Plug the router back in and wait for the internet connection to fully stabilize (usually 2-3 minutes).
2. Power on the printer. If the Wi-Fi lamp is off, press and hold the Wi-Fi button on the control panel until the lamp flashes blue.
3. Access the printer's internal menu: Tap the "Setup" (gear icon) on the touch screen.
4. Navigate to Device settings > LAN settings > Wi-Fi > Wi-Fi setup.
5. Select Manual connect. Choose your network SSID from the list and enter your password. Ensure you are connecting to a 2.4GHz band if your router does not support "Smart Steering," as the TR8620a can occasionally struggle with 5GHz handshakes during initial discovery.
6. Once the Wi-Fi lamp is solid blue, restart your phone and laptop to clear the mDNS cache and refresh the AirPrint discovery list.

If That Didn't Work

• Assign a Static IP Address: The most common cause of recurring disappearances is the router assigning a new IP address to the printer (DHCP lease expiration). Print a Network Configuration Page from the Setup menu to find the current IP address. Type that IP into a web browser on your laptop to open the Remote UI. Navigate to Network Settings and change the IPv4 setting from "Auto" to "Manual," then assign a specific IP address outside your router's dynamic DHCP range.
• Disable "Eco" or "Power Save" Mode: The TR8620a's deep sleep mode can sometimes shut down the network card entirely. In the Setup menu, go to Device settings > Energy saving and disable "Auto power off." This ensures the network card remains active and responsive to AirPrint pings.
• Check Router Multicast/IGMP Settings: Log into your router's admin panel. Look for settings labeled "IGMP Snooping" or "Multicast." If these are disabled, AirPrint (which uses multicast) will not work. Enable IGMP Snooping to allow the printer's discovery packets to reach your mobile devices.
• Perform a Network Reset: If the printer refuses to connect, go to Setup > Device settings > Reset device > LAN settings. This wipes all saved network credentials and clears the internal NIC cache, allowing you to start the Wi-Fi setup from scratch.

Heads Up

• Avoid using a "Guest Network" for your printer; these networks typically have "Client Isolation" enabled, which explicitly blocks AirPrint and other local discovery services.
• If you use a Mesh Wi-Fi system (like Eero or Google Nest), ensure the printer is placed within 15 feet of the nearest node during the setup process to prevent signal attenuation.
• Keep the printer's firmware updated via the Setup menu to resolve known bugs regarding wireless stability and AirPrint compatibility.
• If you see a "Connection Error" on the screen, check if your router is using WPA3 security; the TR8620a works most reliably with WPA2-AES encryption.