DIAGNOSIS The most common culprit is the wireless band or security type mismatch between your router and the printer.
FIX Force the printer to connect on the 2.4 GHz band of your network.
- Go to your router's settings and temporarily disable the 5 GHz band, or ensure your 2.4 GHz network has a distinct name (SSID).
- On the printer's control panel, navigate to Menu > Network Settings > Wireless LAN Settings. Select your 2.4 GHz network and enter the password carefully, checking for caps lock.
IF THAT DIDN'T WORK The printer's wireless module may need a reset. From the control panel, go to Menu > Network Settings > Reset LAN Settings, then try the setup again from scratch.
HEADS UP WPS (Wi-Fi Protected Setup) is notoriously unreliable on these. Skip it entirely and use the standard manual SSID/password method.