If MAC address filtering is enabled, register the printer’s MAC address so that it is not filtered. See the documentation provided with the wireless router for details. You can check the printer’s MAC address from the Network Status section of the Network Connection Report.
If your wireless router is using shared authentication with WEP security, make sure the authentication key and index are correct.
If the number of connections allowed on the wireless router is less than the number of devices that you want to connect, reconfigure settings on the wireless router to increase the number of connections allowed. See the documentation provided with the wireless router for details.
Turn off the wireless router. Wait for about 10 seconds, and then turn it on.
Reconfigure the printer's network settings.