Updating firmware on unlocked iphone
If nothing, read and perform methods (1,2,3,4) described above. Just try every of them and read every no service fix very carefully.
Also while your i Phone is on, pop the Sim card out and turn off the power. Or, turn i Phone on, pop up the Sim card, turn i Phone on and insert Sim card. If they already on – turn it off and wait for the signal. If methods above don’t work to fix No Service on i Phone, you can try the third method which is the best because it works in 90% cases: 1). Other reason of No Service on factory unlocked i Phone is the antenna of your device.You may also want to connect your i Phone to your local Wi Fi network, so you don’t get charged for downloading the update over your cellular connection. i OS will automatically check for available updates and will inform you that i OS 7.1 software update is available. Wait for the download to complete and then tap Install to apply the update.If you get tired of waiting for the download to finish (it could take a while) then go do something else.And remember, if i Phone got No Service issue it doesn’t mean that it is not unlocked.If device would still be locked it never accept and activate i Phone with other Sim card.Wait for i Tunes to open and connect to your device.
Click on your device in i Tunes and then click the “Check for Update” or “Update” button as you can see above in the Summary pane.
If an update is available, i Tunes will prompt you to download and install the update.
Wait patiently and do not disconnect your device until the update has finished.
If your phone is not unlocking or getting signal, PLEASE perform the backup/restore once again (above).
Sometimes it takes upto 3 times to get it provisioned and unlocked. Best way is by putting in a GSM (NON supported sim) and seeing if you can dial out.
Note: First try just Restore, without holding Shift/Option. After the process you will have service and can make calls. Very often when you try to cut the Sim card yourself many do it wrong and i Phone can’t detect the Sim. In this case just contact or go to the Apple Store and ask them to check it for you.