Check the following.
Other devices on the network are turned on.
Network addresses (IP address, subnet mask, and default gateway) are correct if you have set the printer’s Obtain IP Address to Manual.
Reset the network address if they are incorrect. You can check the IP address, subnet mask, and default gateway from the Network Status part on the network connection report.
If DHCP is enabled, change the printer’s Obtain IP Address setting to Auto. If you want to set the IP address manually, check the printer’s IP address from the Network Status part on the network connection report, and then select Manual on the network settings screen. Set the subnet mask to [255.255.255.0].
If still does not connect your printer and network devices, turn off the wireless router. Wait for about 10 seconds, and then turn it on.