Unable to restore Iphone 3g after itunes restore

[nelynge]

I bought a second hand iPhone 3g, with iOS 3 something, it was jailbroken.
I wanted to update it to 4.2.1, I thougth that using the update feature on itunes I would be able to update it, and later jailbreak it.
But when I did the update, it got stuck with the following message on iTunes:
"The sim card inserted in this iphone does not appear to be supported".
I'd tried to use redsn0w to jailbreak it and unlock it, but it never finish the jailbreak, it's supposed to show a lot of text messages on the screen after rebooting, but it doesn't. Any other unlock solution depends on using cydia or some other tool, but I can't get past the screen of USB connecting to iTunes.
By the way I can't get the original sim card of the phone, i don't even know for which country.
I really need help to fix this.

 

[JunkyDog]

try snowbreeze v2.5.1 and make a ipsw and restore via itunes by pressing shift and restore, then select the newly made ipsw. snowbreeze opens up your iphone, we call it (h)activate..

 

[kimberleyallen]

Jailbroken iPhone 3G problems

I wonder if someone can help me with simple instructions as I'm inexperienced!

My daughter has a jailbroken 3G iPhone. She was having problems with it and so updated the software through iTunes. Now she can't access the phone at all, it is just showing an iTunes logo and usb pic. When you restore it through iTunes it comes up with the error message saying something like ' only compatible sim cards from a supported carrier.' She doesn't know what the original carrier is. As you can't access the settings she doesn't know which firmware version either.

I have downloaded all the recommended programs and followed the instructions on each several times but have made no progress. Can anyone help?!
Many thanks