Just recently, I open it up and wifi connects but it says no internet. All other devices (iPhones, sonos, pcs) work fine. After playing, deleting, restarting it seems to work but it's a pain. Any thoughts?
Go into your System Preferences->Network pane and at the top of the pane is 'Location' toggle bar. Use that to 'Edit' to make a new custom named Location and save that new Location. Then rejoin your wireless network.
Another fix is go in /Applications/Utilities/KeyChain Access and find your wireless network saved password and delete it and then rejoin your wireless network and save the right password again.