The radio on my phone wont' turn on

If the radio won't turn on it generally means it is not within coverage or the phone's account is deactivated. Take the battery out and leave out for 2 minutes. Put the battery back in and the radio should come back on. If it does not then go through the menu to bring the radio back online.

You can also try this:
https://www.wireless.att.com/support_static_files/KB/KB37092.html

These phones are also known to have issues if the sound is turned on for some reason, try turning the sound off and back on.