Simple question: Will it work?
Simple question: Will it work?
Jailbreaking allows a user to install third party applications, software, themes and removes the limitations that are on the apple device. In short it gives the user the root access to iOS.So it has got nohing to make a sim work with the phone.If the iPhone 3GS is locked with a different network then T-Mobile sim will not work with it.You need to unlock it.To unlock I suggest you can approach Onlinegsmunlocking.com and remove the network lock using their permanent remote unlock service.