I thought it may be then antenna unit so I replaced it for a new one but still no service. Its an iPhone 3G 4.2.1 05.13. I dont understand what can be the issue. I tried resetting network settings, resetting all settings. Restored with original firmware and jailbroke with redsn0w. Cant figure it out.. at this point my head is spinning and cant clearly think of anything else. Am I missing something?