Go to /private/var/root/Library/, delete original lockdown folder and put this lockdown folder after you extract it from the zip file
Restart phone
If you are not jailbroken:
Sherif Hashim discovered that you can activate your iPhone 4, iPhone 3GS or even iPhone 3G without the original carrier SIM card. You need a “phonebook sim card” or 02 simcard. You can buy these type of sim at radioshack, bestbuy or other mobile electronics store (for example here).
Once you get passed the Emergency Call screen, connect to Wifi, jailbreak using JailbreakMe.com and unlock using ultrasn0w. Once that is complete you should be passed activation and unlocked (able to use any sim). If you get a different simcard error, do the following final step:
Go to /private/var/root/Library/, delete original lockdown folder and put this lockdown folder after you extract it from the zip file
Restart phone
If you have itunes invalid response problem:
Connect to wifi and ssh to your phone (via winscp, putty, terminal, etc).
Navigate to your lockdown folder (/private/var/root/Library/).
Delete pair_records folder
Reconnect the cable and see that your invalid response problem is gone.
If you bought your iPhone 4 on ebay you will need the official sim (at&t) or a universal sim, like ones you can grab at bestbuy for $10 this will get you passed Emergency Screen.
MuscleNerd tweeted today that the recent redsn0w utility is able to jailbreak the iOS 4.1 beta2 on iPhone 3G and iPod Touch 2G. This is useful for developers only, however good news for everyone.
Here’s some info from the DevTeam wiki page:
If you’ve updated to 4.1beta2 on iPhone3G or iPod2G(non-MC), you can use this redsn0w from June to jailbreak. Just point it at the 4.0 IPSW (the public one, not the developer GM one).
(Yes – point it at the 4.0 IPSW even though you’re at 4.1beta2).
Don’t do this if you need the ultrasn0w carrier unlock!!
Note 1: This won’t hacktivate your iPhone3G – but for those with legit access to the 4.1beta2 this shouldn’t matter. Please don’t pirate Apple software
Note 2: If you’re at 4.1beta2 you’ll probably experience network problems after jailbreaking. Until a new version of redsn0w is released, you may need to rely on afc2 access (such as FunBox-like file browser programs) to manipulate your filesystem.
Note 3: This is recommended only for power users who can deal with the problems that will pop up as the JB apps fall further behind the beta firmwares.
Run RedSn0w and point it at the 4.0 IPSW. (Yes – point it at the 4.0 IPSW even though you’re at 4.0.1). This will also hacktivate your iPhone3G at 4.0.1 if you haven’t already been activated by iTunes.
Install ultrasn0w in Cydia (add repository http://repo666.ultrasn0w.com) if you need a carrier unlock (and in the USA, remember to turn off 3G mode in Settings→General→Network).
Congratulations to all iPhone users. iPhone 4 has been successfully jailbroken. iPhone hackers @planetbeing and @chpwn has managed to get root access on the device using @comex’s userland jailbreak method. However do not expect new jailbreak utility soon. @p0sixninja has confirmed that it cant be released in its current shape because it contains some of Apple’s proprietary code:
@i_Enthusiast the jailbreak shown is a more of a stepping stone for us, it can’t be released because it includes some of apples software
You should not expect the carrier unlock soon too. This is because iPhone 4 uses a new baseband OS, which will require a complete rewrite for ultrasn0w unlocking tool:
The DevTeam and others have been checking through the iPhone 4, and have noticed the baseband runs a completely different OS than on previous models. The iPhone 3G and 3G[S] both ran Nucleus OS on the PMB8878 baseband CPU (aka XGold 608), where the iPhone 2G ran the PMB8876 (aka S-Gold 2). iPhone 4 uses the PMB9800, or X-Gold 618 – running a separate OS – ThreadX, an RTOS by ExpressLogic.
Good news from DevTeam. They just announced via twitter that unlock for firmwares 3.1.3 and 4.0 is ready:
RT @MuscleNerd: ultrasn0w tips: 1) Works for all basebands since 3.0 FW 2) Remember to disable 3G on T-Mobile USA
ultrasn0w 0.93 released! Cydia repo is repo666.ultrasn0w.com. Works with basebands 04.26.08 thru 05.13.04
This means, that all users with basebands 04.26.08, 05.11.07, 05.12.01 and 05.13.04 can use ultrasn0w 0.93.
There is no jailbreak for just released iOS4, so you need to wait a bit. Firmware 3.1.3 who need unlock can update ultrasn0w and use their iPhones with any carrier.