iPhone 4S unable to find wifi networks.

My iPhone 4S is unable to locate any wifi networks.  It shows that it searches for a network, but it never finds one, even when I set the phone on the router.  I replaced the wifi antenna with no change.  I restored the phone, without backups, with no change.  When I check the Bluetooth setting, it appears to be on, but it doesn't give any options, and the icon just spins like its searching.  I don't think there is anything to find though.  Any ideas?