Requirements : 1 . Custom firmware for Device : ———————————————— Download custom firmware iPhone 4 /Activated ——> { <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> | <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> } Download custom firmware iPhone 4 /Unactivated —> { <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> | <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> } ———————————————— Download custom firmware iPhone 3Gs /Activated ——> {<Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> | <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> } Download custom firmware iPhone 3Gs /Unactivated —> {<Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> | <Bạn vui lòng đăng nhập hoặc đăng ký để xem được nội dung này!> } Guide : 1. Connect your phone with PC and switch off 2. Open iREB R4 and follow olders 3-After that open itunes and press “Shift + Restore” and choose custom firmware 4.3.3 (Alt + Restore for Mac Users) it will finish very quickly 4-Finally you can see your phones is with your old Baseband. now just you can install the ultrasn0w 1.2.3 from Cydia ———————————————— Booting in Tethered Mode (Mac Users) This is tethered jailbreak so you have to run this small tetheredboot utility by following these steps. Download and Extract the tethered boot .zip file . [Download tetheredboot.zip] we need two files from the custom iOS 4.3.5 firmware namely:kernelcache.release.n90 and iBSS.n90ap.RELEASE.dfu. To do this, make a copy of your custom iOS 4.3.5 file that you created above, change the extension of this file from .ipsw to .zip, and then extract this .zip file. Now copy kernelcache.release.n90 file, and then copy iBSS.n90ap.RELEASE.dfufiles which are found under /Firmware/dfu/. Move all these files, and tetheredboot utility to a new folder named “tetheredboot” on the desktop. Commands Turn off your iOS device, and start Terminal on OS X and run the following commands: Code: Mã: sudo -s enter your administrator password, then: Code: Mã: /Users/Tech/Downloads/tetheredboot/tetheredboot/Users/Tech/Downloads/tetheredboot/iBSS.n90ap.RELEASE.dfu/Users/Tech/Downloads/tetheredboot/kernelcache.release.n90 You need to replace “Tech” with the name of the directory on your PC. If the command given above does not work you can always try ‘tetheredboot -i ibss -k kernel’ instead of ‘tetheredboot ibss kernel’: Code: Mã: /Users/Tech/Desktop/tetheredboot/tetheredboot –i/Users/Tech/Desktop/tetheredboot/iBSS.n90ap.RELEASE.dfu -k/Users/Tech/Desktop/tetheredboot/kernelcache.release.n90 You should now see some code running in the Terminal window, at some point, it will ask you to enter DFU mode. Now follow the following steps to enter DFU mode: Hold Power and Home buttons for 10 seconds Now release the Power button but continue holding the Home button for 10 more seconds You device should now be in DFU mode Now wait for your device to boot, Terminal at this point will be showing “Exiting libpois0n” message. After a short while, your device will be booted in a jailbroken tethered mode ! Booting in Tethered Mode (Windows Users) Since this is a tethered jailbreak, therefore whenever your iOS device loses power, it will go into the dreaded Apple logo boot screen loop. To get out of that, simply run Redsn0w 0.9.8b4, uncheck “Install Cydia” and instead check “Just boot tethered right now” option and hit “Next” with your iPhone, iPad or iPod touch connected to your PC (or Mac). And yes, you will have to do this every time when your device reboots or loses power. WARNING: If you depend on UltraSn0w unlock, you must STAY AWAY from RedSn0w and stock iOS 4.3.5