Help. SIM card not supported

Obviously.
Did you have it JB and unlocked?
You cant do either now on 4.0.2
Did you have SHSH's saved thru cydia for previous builts so you can downgrade?

 

If you didnt save Your Shsh files thru cydia or tiny umbrella then your toast. Wait until the next jailbreak.

 

Borrow or buy (Ebay) a sim from the carrier who sold the phone to activate it.
Use model # to figure out official carrier info.

 

There is no lockdown file.
You need to activate it with the carriers sim that its locked to.
You know what company its locked to? USA AT&T?
You can purchase any inactive sim of that company thru ebay or whatever and activate it and then JB with jailbreakme and install ultrasnow thru cydia to unlock.

 

yes there is...

Well I think he refers to the trick to use a Phonebook card (which is used to copy contacts)... before aug5 it use to let you bypass the activation screen and you could run and restore to older firmware, i don't know if using the Phonebook card would still work, they usually go for like $5.... (The best would be to get either a prepaid card of the original company).

There is such a thing as lockdown the location is here: /var/root/Library/Lockdown/activation_records/wildcard_record.plist
And people replace the wildcard plist when they put another sim and the phone tells them "different sim detected" so they go through SSH and change it to the other plist that was used in the older jb... these people can receive calls and txt, so they just remove the sim card, they go to the homescreen, cydia, ssh and then replace to the older plist form previous jb

 

Well I don't know about that one, if you are really sure it came from the US, then a Prepaid or normal AT&T 3G sim card is the one you would need and you can be sure it will work...

 

But obviously you cannot SSH or change any file unless you JB it.
And in order to JB it you need to activate it first. So dont give him any false hope for editing any lockdown file. Only way to JB it right now is to activate with either an official sim or a thing called a phonebook sim and those are not easy to find and you gotta make sure you get the correct one that will work.
Not sure what company or site sold it though. But it would be just as easy getting a sim of the carrier that the phone is locked to online or thru ebay.

 

Yes, that sim claims that it will activate USA apple iphones.
Also any of these sims will do the job too.
http://shop.ebay.com/?_from=R40&_trksid=m570&_nkw=usa+at&t+sim+card

 

I didn't think I was giving him false hopes since "SIM card not supported" (like his) is a different message than "different SIM detected" (which people can receive calls and txt), maybe I should have stated that since the OP may have misread the paragraph description, but I just wanted to say that lockdown exist and for what is used since maybe people didn't know of the trick and found it interesting to know.... the best and easiest way for the OP is an AT&T sim.