At last, Apple has released iOS 4.2.1 which was expected to be released as iOS 4.2. Besides iPad, iOS 4.2.1 update means a lot for iPhone 3G users. If you update iPhone 3G to iOS4, you would have remembered the poor performance of iPhone 3G. It was promised to fix the issues in iOS 4.1 and it did but it was never like iPhone 3GS. It looks like Apple has managed to fix a lot more in iOS 4.2.1 for iPhone 3G and performance is much better.
iOS 4.2.1 or iOS 4.2 has been available since months to developers and they were able to test the adjustments for iPhone 3G and give feedback. Obviously, a lot of users would like to jailbreak iPhone 3G 4.2.1 and free there iPhone from Apple’s control. iPhone 3G users are lucky as their handsets contain old bootrom which are prone to untethered bootrom exploit for life. Jailbreaking iPhone 3G 4.2.1 is also not different.
iPhone Dev Team has released redsn0w 0.9.6 b4 which now fully supports jailbreaking iPhone 3G 4.2.1. Remember, it is an untethered jailbreak and you don’t need to worry plugging in your iPhone 3G 4.2.1 on a restart with PC/MAC.
Warning: If you are using ultrasn0w unlock then you should stay away from upgrading iPhone 3G to 4.2.1 for now. However, iPhone 4.2.1 unlock for your device is hopefully coming this week. Until then, hold back from iOS 4.2.1.
Here is a step by step guide to accomplish iPhone 3G 4.2.1 jailbreak. Before proceeding, make sure that you have grabbed following items.
Step 1: Upgrade your iPhone 3G to final build of iOS 4.2.1.
Step 2: Launch redsn0w and click “Browse”. You have to select iOS 4.1 for iPhone 3G to move forward. [Remember, it is 4.1 firmware]
Step 3: Cick “Next” and redsn0w will start preparing data to jailbreak iPhone 3G 4.2.1.
Step 4: Select the options you want to enable along with “Install Cydia”.
Step 5: Turn off the iPhone and connect with computer.
Step 6: Now, follow redsn0w’s instructions to get iPhone into DFU mode.
Step 7: You can take a rest while redsn0w finishes the installation. Once it reboots, you will have a jailbroken iPhone 3G 4.2.1.
Other Jailbreak Guides and Notes:
{ 27 comments… read them below or add one }
I have done all above and it was OK. But when operating the screens or applications the display is blinking rapidly.
Thank You, its working for my 8GB Iphone 3G, but its continuously blinking when i slide the icon or working with the icon… can u help me to fix this Thank you
same here. how did you solve it?
I have the exact same problem!
Yess…. now is working fine…., try the steps once more, and i choose firmware 4.2.1 …. thank you…..
Am having the same problem (blinking), 8Gb 3G. Any solution?
Just like heri said. if you get the blinking screen once you jailbreak it, you will need to jailbreak it again, but use IPSW 4.2.1 instead of the 4.1 they say to use in the tutorial. it worked for him and worked for me too.
i'm having the same blinking problem + i can't run cydia. It opens for a few seconds than it closes and nothing more happens.
Those people who are not able to restore 3G after getting stuck with jailbreaking/unlock 4.2.1 with bb 06.15
1) restore iPhone back to 3.1.3, error would show up 1015, ignore it
2) download recboot (www.mediafire.com/?nn1kzmmwkjg) & unzip it, install setup file libusb-win32-filter-bin-0.1.12.2.exe (Win7 rgt-click properties-run as admin and winxp sp3 compatibility mode).
3) run Exit.bat – iPhone will restart
4) use redsn0w-win_0.9.4 & point it to 3.1.2 ipsw
5) iPhone will jailbreak to 3.1.3 bb 06.15
6) iPhones with working wifi can goto Cydia and install unltrasn0w 1.2
—-
iPhone without wifi
1) download SetupiPhoneBrowser.1.93.exe – http://code.google.com/p/iphonebrowser/downloads/…
2) download ultrasn0w 1.2 .deb – http://www.megaupload.com/?d=UJKGUM4A
3) Open iPhoneBrowser – (Create folders Cydia and AutoInstall right after Media) in var/root/Media/Cydia/AutoInstall
4) Drag & drop ultrasn0w and mobile subrate insiide AutoInstall folder
5) Restart iPhone twice, carrier will come up and enjoy
So you have to use 4.1 firmware in Redsn0w? I have been trying to jailbreak my 8gb 3g, but Windows would keep encountering a problem during jailbreak. Is that the reason.?
Thanks!! i did, and it works!
and my 16gb 3G had the same, "blinking screen"
but i did it again with the iOS 4.2.1 and now its cool!!
Thank you very much, now im going to try unlock it!
Hi,
I’ve downloaded IOS 4.1 and 4.2.1 but I can’t find the “IPSW” file with Redsn0w.
Did I downloaded the wrong software or is it something else?
Please let me know:)
works here on iphone 3g, also had to use 4.2.1. redsn0w didnt even let me go forward with 4.1
Did everything i needed to. Now it is super slow and keeps oin back to the black screen with the apple symbol on it. When it does get to the screen with the green battery, I tried to use the slider to unlock, and nothin happens at all. The iphone keeps going in circles by itself like this.
When you are jail breaking and unlocking, Does the SIM card that will be used need to be in the iphone, or can it remain out?
I also restored the iphone 3G and tried to reinstall the jail breaking and unlocking software, and I am still having the same problem. It is super slow and seems to be working on its own by selecting things to keep going in the same circles. It goes to the apple screen, then oes to the “slide to unlock” screen, then it shows my apps, then it turns off, then back on and back to the apple screen.
When you are jail breaking and unlocking, Does the SIM card that will be used need to be in the iphone, or can it remain out?
I also restored the iphone 3G and tried to reinstall the jail breaking and unlocking software, and I am still having the same problem. It is super slow and seems to be working on its own by selecting things to keep going in the same circles. It goes to the apple screen, then goes to the “slide to unlock” screen, then it shows my apps, then it turns off, then back on and back to the apple screen. It acts af if the slide to unlock is frozen, and will not move when I try ti slide it.
I was getting stuck on "Uploading ramdisk" in redsn0w
I am on Win7 x64 quad core
I saw this in forum : http://osxdaily.com/2010/11/28/redsn0w-0-9-6b5-do…
you need to put the redsn0w program on Highest priority and affinity on ONLY CPU 1 (right-click on the process in the task manager)
It works great for me !
cant find firmware
hi can u help me. i am useing iphone 3gs 8gp. i get struck in 2nd step. i not able to find the iphone1_2_4.1_8B117_Restore.ipsw….
can u pls help me to jailbreak my iphone
theres a video on youtube that walks you thru changing from .zip to .ipsw
very easy. I had the same problem.
thank you lots for this perfect guide. I have done so many of the more recent versions of the iphone than the plain 3G one I offered a friend to do yesterday that I overlooked the minor differences in technique. Nothing was working and I was getting a little embarrassed at the trouble I was encountering using all BUT this particular set of prerequisites, namely the redsnow 0.9.6b4 (exactly — the newer revisions produced errors to my dismay) in conjunction with the 4.1 firmware for the 3G even though the restore was to fully factory 4.2.1.
So happy I ran across this particular post. Typically I almost never spend the effort to post my results (good nor bad), but this instance called for it since I hope anyone else who happens to fall into this exact circumstance finds this post and shares the good fortune that it brought to me.
Thanks again…saved the day!
–jonathan
the proccess keeps stopping after the second stage and saying wating for the reboot… dunno whats wrong
i have just done this succssefully but when i go onto app store it asks me for password and when i go to apps that charge it asks me do i want to buy it will i be charged for this ??
i keep getting stuck on uploading ramdisk. it just sits there for a long time. I have the right firmware. what should i do?
when you select the firmware, type in '.ipsw' at the end of it and then click open. it worked for me
from the step one mean we have to upgrade the iphone 3G to ISO 4.2.1 before start step 2? my iphone 3G currently running at ISO 3.0.1 jailbreak and unlock. can i just go to step 2? pls advice.
Just a heads up- if you already updated to itunes 10.2 the whole process will still work. no need to downgrade to 10.1
hope this helps