Try doing a hard reset. Dial #002# and hit then send key. After you get the confirmation it worked, take the battery out and leave it out for ten seconds.
Posted from my CrackBerry at wapforums.crackberry.com
still no service! T-Mobile thinks it the device. This will be my third device. the last one wouldn't take a charge. and that battery pulling is getting tired. these things cost so much money they should work right. just me venting. now breath!