Aloha from Hawaii... I was having trouble with no 3g service yesterday, and this is what FIXED it.. hit the menu/drawer button and click on the ACTIVATE icon.. you will see a countdown like 3....2....1 then you will get a ERROR (this is NORMAL, your already activated!) but it will reregister your phone with the network and your 3g should work fine! I did this yesterday, 3g worked all day, then turned phone off, and this morning the 3g is STILL working! Try it and see if it works for you! ALOHA!