iphone problem

[mapex]

New to the iphone after buying a 6 month old 3g, so i got a few
apps then went for a sat nav and it told me i need number 4 firmware, i
think it was on 2 something. I used itunes to upgrade and it backed
a few things up i,m sure.
When i upgraded it told me my sim was wrong provider, i then looked up
how to downgradde thinking this would unlock it again, it never.
Now i,m left with a locked phone and a picture of the itunes connection
on it.
Was thinking of taking it to a shop but decided to join the forum and ask.
The guy i bought it from took it to a shop and got it unlocked
now my upgrade has locked it again.

Thanks

[Canker_Canison]

If you check out the Iphone section you will find what you need.

But very quickly....

If you now have OS version 4.2.1 you can jailbreak straight away, if not you need to download 4.2.1 for the 3G & install it via DFU & pressing SHIFT while clicking RESTORE on Itunes. You can download the update from here

Download RedSn0w 0.9.6 beta 5 as well as iOS 4.2.1 for your iPhone from here

The chances are you will need to upgrade the baseband to 06.15.00. Start Ultrasn0w & follow the instructions. When you get to make some selections make sure you have INSTALL CYDIA & INSTALL IPAD BASEBAND selected.

Once everything is installed you need to update Cydia & search for Ultrasn0w, once found install & restart.

Be advised, you will need to have a SIM from the host network. So if it is locked to O2 you will need an O2 SIM to activate the phone. This method will mean you cannot roll back to a previous baseband or OS version, updating will also be a problem until Apple update the baseband on the 3G to anything above 06.15.00