As you are probably aware Apple recently started selling unlocked iPhone 4s on its website and in retail outlets in the US. Now we have an article looking at a non-jailbreak iPhone 4 converted from AT&T to T-Mobile.
Lex Friedman of MacWorld.com has written an article on how he converted an unlocked iPhone 4 on the T-mobile network. Even though T-Mobile does have a 3G network, it has different frequencies to AT&Ts. This means a T-Mobile user with an iPhone 4 will have to make do with slower EDGE data speeds.
Also See: AT&T still down says outage map
So if you don’t mind having slower data speeds you can have an iPhone 4 on your T-Mobile account, but it will take you a bit of work to get there. First up you need a T-Mobile Sim card if you don’t already have one. But the first problem you will encounter is the fact it will need to be made smaller. There are special tools to do this quickly, or with a bit of care you can use a sharp knife.
You will also need a pen or marker, and maybe even a cutting board as well. You will find a SIM removal tool which you will need to open the SIM card tray. You will then need this tray to use as a template to cut around your SIM card, making sure you don’t damage the shiny part.
Take your time to slowly trim down the card, and once this is done you can insert it into the device. When you turn on the phone if you are met with a No SIM message try putting the SIM in again. Once this part is successful after a short time it should connect to the T-Mobile network. You will then need to connect to iTunes and let it do the initial sync, now disconnect the device.
Now after all your hard work you should be able to make calls and send text messages via the T-Mobile network. Things like Visual Voicemail and MMS won’t be possible though. Other than that it should work as you would expect it to, and you can install apps and update with iTunes.
Would you consider attempting something like this?