I think I know the answer to this....

[glen e]

1 year old iphone 4 suddenly in the middle of a phone call this morning, drops call and 4 hours later, it's still "searching" for network

wife's iphone shows good signal, have done a restore and running the latest update, done a hard reset...no avail...

genius bar time?


or is there something else I can check?

 

[Applejuiced]

Setup as new.
Take out sim and make sure it sits right in the tray.
Bring to Apple if still nothing.