Learned the lesson the hard way again. 🙁 🙂
I think nowadays jailbreak is not as popular as the early days of iPhone. And I did that also to my iPhone 3g, reason being I don’t want to stuck in contract with AT&T, so I jailbroke it and put in T-mobile prepaid card, and gave it to my wife. Now the consequence part.
Recently I want to sell this phone, as we no longer use it. We probably have not touched it for couple years. Since I gave my old iPhone 4 to my wife about 2 years ago. And I made a mistake put it in “factory unlock” category for this phone, which is not true. I found a buyer. But when I tried to remove the content of this phone, by going to settings, it got stuck. I had to put it in DFU mode by following this instruction. Also I had to upgrade it to iPhone 4.2.1, which is the last updated version of iPhone 3g. After that obviously I lost the jailbreak, as it does not take a T-Mobile SIM card to activate. Luckily I found a H2O (AT&T network) SIM card, and I was able to activate the phone. Note in the early days of iPhone, a SIM card is required to setup an iPhone. I was also be able to restore the content from iTunes backup after that, which is cool as I did not backup the contacts on the phone previously.
Long story short, I had to cancel the order, and put it on sale again in “AT&T” category, as this is no longer an unlocked iPhone. The morale of lesson here is jailbreak is not “factory unlock”, it consistently need to keep up once we update the phone, which is a hassle. Had I stayed with AT&T, I would get an unlocked code, and get it unlocked officially. Just like what I did with the old iPhone 4.
I thought about it more, since I paid the early termination fee, and I requested for device unlock via AT&T website. Did it couple times, and it worked. The first time it did not work due to my own mistake, they asked for email confirmation in which I need to confirm my email by clicking on the link. After the carrier unlock, I was able to restore the iPhone 3g to iOS 4.2.1 and use a T-mobile SIM card to activate the phone. Now I put it back in Apple iPhone 3G 8GB Black unlocked category on Amazon again.