Hello,
Here are a couple stabs in the dark.
1. You can try a battery pull to reboot the phone. Turn the phone off. Then pull the battery out for about 30 seconds. Then reassemble and power back up.
2. You could try holding the phone in your left hand with the screen facing to the right (so if you raise up your hand to your chest you can see the screen). I think the antenna is toward the top of the phone and in front. Oh, and make sure the top of the phone is also pointed up.
Good luck!
