Upgraded my (unlocked) iphone 3gs to iOS 4 version but sim card is not accepted

[claudiadast]

Hi, I live overseas and recently bought an unlocked iPhone 3GS that I had hooked up to iTunes. Everything worked fine and my sim card from this country was valid. When I disconnected it and reconnected it, a sign popped up saying i could upgrade to iOS 4 or something, so I clicked update. Then, it starting backing up my iPhone and restoring it, but when it was finished and I reconnected it with iTunes, a sign came up saying that my sim card is not valid. Why would it say that when it had accepted it in version 3.1.3? Now, I was thinking maybe if i just re-inserted my sim card again it would work, but i'm having difficulty getting it out of its hard case. Is that what the problem is, or is it worse?

I just tried downgrading it back to version 3.1.3 from the iOS 4 version, restoring it to its "Factory Settings" but it still gave me the same message: that my sim card isn't valid.

please help!

 

[Applejuiced]

Because it was JB and unlocked.
Thats what happens when you update it to official firmware. It locks again.
It was not forever/factory unlocked.

 

[MaxBurn]

Oh boy, sounds like you don't have a factory unlocked phone? True?

if so you just updated the baseband and lost your unlock. What baseband does it show now? Settings, General, about, modem baseband

 

[claudiadast]

So what does that mean now? Do I have to go get a new sim card or get the phone unlocked again? or both?

 

[Applejuiced]

You dont need a new sim.
You have to JB and unlock it again.
And next time dont upgrade to stock firmware cause you might lose your unlock for a long time.
Follow this:
http://www.iclarified.com/entry/index.php?enid=12945

 

[EricNau]

Please don't post multiple threads on the same issue. From the Forum Rules:

One thread. Do not post a thread more than once. Post a new thread in the proper forum. If the topic is relevant to more than one forum, pick the best fit or most specific forum and post it only once.​

I merged both threads, so all responses can now be seen here.

 

[claudiadast]

So, since I upgraded, but then restored it, what baseband would it be now? I can't check because it's stuck on the screen telling me to connect it to iTunes with the emergency call option. Before, it's baseband was 5.12.01, so do I still use this same baseband when using the jailbreaking and unlocking software? Speaking of which, which software am I supposed to use, whether it's redsnow, ultrasnow, blackrain, etc.?

 

[Applejuiced]

If you restored recently then you updated it to 4.2.1
Use the guide I gave you above.
Thats the only way to unlock it now.
You might lose your GPS capabilities though.
Attempt at your own risk.