Unlocking iPhone 4 by Cellular Service Provider

[miles]

I have called my cellular service provider and asked them to unlock my iphone 4 since it's an outright purchased and I'm in no contract to them. They have agreed to unlock it on their side. I was told to insert a different carrier SIM to the phone, then go to iTune and do a restore / update.

So, I put a SIM of a different service provider and connect the phone to iTune. An "Invalid SIM" error popped up in iTune. After I acknowleged it, it closed the window but it no longer show the iphone connection. Therefore, how could I go to the restore option since the "Invalid SIM" error disconnect the iphone from the iTune?

Any help will be appreciated.

 

[willerz2]

Unplug and re-plug your iPhone and it'll show up in iTunes again. Carrier/IMEI unlocks are rarely instantaneous. It does take time for it to take effect based on the whitelist refresh rate. Normally it would take anywhere from about an hour to a day to take effect. You'll know that the unlock has gone through when after you restore in iTunes, you'll get a "Congratulations" message.

 

[miles]

Do I need to upgrade the software to the latest iOS (6.1)? Or an older iOS and jailbroken will do? Would the "congratulations!" show after the restore or before? Again, thank you.

 

[willerz2]

The congratulations shows after a restore, and it doesn't have to be the latest iOS. You can restore using a stitched IPSW back to your current iOS.

 

[miles]

I remember this morning when I tried to restore it in iTune using the default SIM, it showed that it will upgrade the software to 6.1 (by default). How could I keep my existing software during the restore? Should I upgrade it to 6.1 in iTune, then restored it back to 5.1 using stitched IPSW in Redsnow?

 

[willerz2]

Doesn't matter

 

[x98car]

Once the IMEI has been added to Apple's unlock server you don't have to restore. Just put in your different carrier sim and connect to itunes. If iTunes is giving you invalid sim message then the unlock hasn't gone through yet. If it has gone through first you will get a message saying "failed to activate", simply unplug the phone then plug it back in and you will get the "Congratulations your phone has been unlocked" message.

 

[willerz2]

That would be the case if the device is deactivated for the most part. Otherwise, you'll have to manually de-activate it, or, you can restore it. The reason why restores are preferred (particularly when buying online) is to make sure that it's actually a factory unlock and not a cheap backdoor unlock that's erased when you restore. Just a double check to make sure you didn't get scammed is all.

 

[x98car]

You should only have to deactivate it if the phone was initially hactivated when jailbreaking. As long as it was activated normally with an official sim from the carrier it was locked to then a restore is not needed.
What is this cheap backdoor unlock you mention? As far as I know once an IMEI is in Apple's whitelist server for unlocks it's there for good. There is no halfway. Now I have heard some of these dirt cheap IMEI unlocking people on ebay use a method of entering these IMEI's by way of hacked employee accounts, which can then be traced and potentially relocked. Is that what you mean?

 

[willerz2]

In a way, it's like 'flashing' an IMEI or replacing the IMEI chipset. This method is commonly used in China, which is why you would find this method of unlocking mostly from Chinese 'unlockers'. Like flashing the iPad Baseband and UltraSn0w, you're taking advantage of the ActivationTicket upon every boot. Your device will be flashed off of a China IMEI that's then placed onto the whitelist on that end, meaning your device is basically bouncing off of a China IMEI. Like software unlocks, once you wipe the device, you'll lose that little exploit in the ActivationTicket. But at the same time, it works on all devices because it's flashing and not changing the core, so it's undetectable unless you look at the IMEI itself.

Like a bricked iPhone, the IMEI can read straight 0s, or just [] [] [] [] [] over and over again, overflowing off the screen. How they actually manage to do it, that I never got to find out. But like how the Chinese have their methods of piracy, they'll always find loopholes to take advantage of when another gets patched, and quite frankly, they can't exactly root through the whitelist to see which device is unlocked when you have billions of mouths over in Asia. I've seen a backdoor unlocked iPhone before, just never seen the actual process of doing it but that's what I know of of how it works.

 

[x98car]

I have never heard of that method before. Sounds like the physical phone is required to do this and is not done remotely. Is that right?

 

[willerz2]

They can do it both ways apparently. Having the phone physically shorts the process by a good half an hour. I've only known of people that did the physical method.

 

[x98car]

Doesn't sound like that is the case with this OP though.

 

[willerz2]

Nope.