All Custom Firmware (IPSW) Untethered+JB 4.2.1 To 4.3.3 iP4,3,3GS. For all of you out there who don't know how to make a custom IPSW files in this post you will find them already hactivated + jailbroken, all you need to do is to download them and install on the iPhone: This is a 'Retweeted' post from HERE & HERE & HERE. Don’t worry, we have ready made Custom firmware 4.1 for all iDevices just for you. Below you can download iOS 4.1 Custom firmware for iPhone 4, iPhone 3GS, iPhone 3G and iPod Touch 4G, 3G. These custom iOS 4.1 firmwares are created with PwnageTool 4.1 and can be restored via iTunes. (Download links below).

If you accidentally try and upgrade your iPhone 3GS through iTunes after having previously jailbroke it, it will get stuck in recovery mode and fail to restore to the official Apple firmware bundles IPSW. You will get a whole bunch of iTunes errors like 1015.

The iPhone needs to be restored with the custom IPSW used to jailbreak the iphone in the first place.

This guide specifically deals with the iPhone 3GS, on a custom firmware of iOS 4.2.1 or 4.3.3 and an updated iPad Baseband 0f 6.15.00

What you will need is the original IPSW Image from Apple or 4.2.1 or 4.3.3

A Custom Restore Image 4.3.3 IPSW if you have lost your own, one is filed here with a prefix of NO_BB so it will preserve your existing baseband.

Get the latest Redsn0w – RedSn0w — Mac is 0.9.9b7.zip and Windows is 0.9.9b7.zip

1) Make sure iTunes is not running.

Iphone 3g 4.2 1 Custom Firmware

1) Launch redsn0w > Browse – select the original Apple Restore Image IPSW – iPhone2,1_4.2.1 or iPhone2,1_4.3.3

2) Select your correct model according to the Serial Number – let redsn0w parse the image

3) Select only “Just enter pwned phone in DFU mode right now

Put iPhone into DFU mode using redsn0w

4) Follow the steps in redsn0w to get the iPhone 3GS into DFU mode which is going to send the screen to black

5) Launch iTunes, hold the shift/option key whilst clicking on “Restore”, then navigate and choose the custom restore – either your own or the downloaded one that starts with NO_BB (which preserves the existing baseband).

Option/shift click restore to restore iphone from custom IPSW

6) Say a prayer

7) You should now boot up to a familiar screen, happy days!

8 ) Restore data from iTune backup.

Firmware

To Re-Jailbreak

1) Launch redsn0w this time selecting the original Apple restore image – iPhone2,1_4.2.1_8C148a_Restore.ipsw, or iPhone2,1_4.3.3_8J2_Restore.ipsw and only select the option to “Install Cydia”.

FirmwareIphone 3g 4.2 1 custom firmware ipad baseband download

Iphone 3g 4.2 1 Custom Firmware Release

2) It will need to enter DFU mode again, follow the steps and the screen goes black, and then the jailbreak process begins, unix flying bash code and running pineapples.

Iphone 3g Ios 4.2 1 Custom Firmware Download

3) iPhone reboots – install ultrasn0w from Cydia to re- jailbreak the device.