Many mobile network companies lock mobile devices to their networks so that they cannot be accessed by any other cellular networks other than that of theirs. One cannot also use any free network sim cards in their phones if they have bought a phone that is locked with a particular mobile network. To be able to use your locked phone with other network carrier, you are required to unlock the phone with a code which is not an easy job.
This is the reason why it is important to approach a professional to unlock your phone so that you can use the cheapest and the best sim card in the device. We can unlock all makes and models of phone quickly and efficiently with doorstep mobile repair services. This is also beneficial if you are visiting another country and want to use local sim card to avoid expensive roaming charges.
When it comes to the First and Second generation of the iPhone, you have to first take out the SIM tray with a small paperclip. Then remove the screws on both sides of the charging spot and take off the back cover using a little force. Detach the ribbon cable that connects the case to the motherboard and remove the display panel using a spudger.