Depending on your wireless service provider, there are sometimes cases when you need to enable iPhone after it has been whitelisted in the Apple database. We always send necessary information to our customers via email, but here are some important tutorials. People just enter, pay the full price in a Sprint or Apple store, and do it because they paid the whole price having an unlocked iPhone like they can take to any user, if what they actually did was buy a Sprint iPhone sprint without a contract. Read our instructions to check the signal strength on iPhone. 4. Difficulty Issue This issue may also occur if you downgrade the iPhone, which may have gone wrong that it will not read the information about the SIM card now. If iPhone does not have SIM installed, error messages for invalid card or SIM card were not lost. Just a few hours after the update, you can try out the solutions mentioned in this article. Winamp Pc Software. Find my iPhone for free Check for iPhone 4S Find my iPhone (FMI) is a feature that prevents other people from using iPhone 4S when lost or stolen. But if you a non-US citizen who unlocks Sprint iPhone, you can use it in your home country, so you can check out Chronic. Verizon Phones With Unlocked Bootloaders more. If you do not have the original carrier SIM card or you do not want to update firmware, go to step 4. 2. If you have the SIM card from the original network (the network as iPhone is currently locked), set it up .We support iPhone 3G, iPhone 3GS, iPhone 4, iPhone 4, iPhone 5, iPhone 5, iPhone 5, iPhone 6, iPhone 6 and iPhone Unlocker Unlock iPhone directly from the Apple database. Even if your network does not validate your IMSI on each incoming call, you must validate your IMSI if iPhone loses power, loses reception, or switches to another PLMN.