Q: Which devices and firmware versions are supported?
A: In this initial release, the following configurations are supported:

- iPad1: 4.3 through 4.3.3
- iPad2: 4.3.3
- iPhone3GS: 4.3 through 4.3.3
- iPhone4: 4.3 through 4.3.3
- iPhone4-CDMA: 4.2.6 through 4.2.8
- iPod touch 3g: 4.3, 4.3.2, 4.3.3
- iPod touch 4g: 4.3 through 4.3.3


source: Dev-Team Blog

PS. Jailbreakme.com > Easiest & Simplest jailbreak ever.

I have recently just upgraded my iPhone 4 from iOS4.1 to iOS4.3.3.
For your information, I did not use PkgBackup, I simply re-download all the Cydia tweaks that I had been using in iOS4.1 (I write down a list). Amazingly, after re-download and install all those tweaks that I've been using, all their settings are automatically restored as well. I did perform restore from backup in iTunes after the iOS restore. I guess their configuration files are also backup in iTunes.

@victorian,
Please remove your post content in post #26 as the jailbroken apps we all are talking about is different from what you're referring. Your post is going to violate the rules in LYN. The jailbroken apps we ppl here are talking about is the one installed in Cydia, mostly tweaks or customizations for iPhone.

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Added on September 20, 2011, 11:00 pmPossible only if you have SHSH blob for iOS 4.3.3 saved.

This post has been edited by huiqing88: Sep 20 2011, 11:00 PM

Your iPhone? iPhone 3GS or 4?
You may head over here

This post has been edited by huiqing88: Sep 21 2011, 03:07 PM

Both official and custom firmware also can IF AND ONLY IF you have SHSH blobs saved

You can upgrade to 4.2.1 with your previously saved SHSH blob. No need to go through 4.3.5.

You can only upgrade/downgrade to any iOS version IF AND ONLY IF you have the SHSH blob for that particular version SAVED.

Yes. Through TinyUmbrella. Or Cydia will also help you to save them.

The method in the link you given is by modifying host file which will direct iOS restore verification to saurik's server, which only work if saurik's server has your SHSH blob saved previously. So it's the same thing, you NEED SHSH blobs (whether locally or on saurik's server) to restore iOS to the version Apple had officially stopped signing.

A lot of ppl upgrade/downgraded/restored their device without knowing that they actually have SHSH blob saved somewhere; in the end they just tell everyone that upgrade/downgrade/restore can be done without SHSH.

GUYS, YOU NEED SHSH BLOB FOR UPGRADE/DOWNGRADE/RESTORE THE IOS TO ANY VERSION WHICH IS NOT CURRENTLY SIGNED BY APPLE.

Ask your friend to connect his iPhone to PC, then run TinyUmbrella.
Check the option "Request SHSH from Cydia" in Advanced tab then try to hit Save SHSH.
If the SHSH blob for 4.3.3 is there, then he can downgrade to 4.3.3 and perform untethered jailbreak by visiting jailbreakme.com on his iPhone.

Try to use this to kick out of recovery mode.

OK, first, is your iPhone factory unlocked?
And what is the version of your current (before upgrade) modem firmware? (baseband)
Cause when we upgrading to iOS4.3+ there will be a baseband checking.
Last time when I upgrade from 4.1 to 4.3.3, I did not check the option "Update iPhone 4 Baseband" in TinyUmbrella, it will cause an infinite recovery loop.
But make sure your device is factory unlocked version before doing this.

You can now try (if your device is FACTORY UNLOCKED):
1) Connect your device to PC.
2) Put your device in DFU mode. (Press and hold the Home button and the Power button at the same time for 10 seconds, then release Power button but keep pressing Home button for another 15 seconds, you'll see nothing on screen)
3) Start TinyUmbrella, click Start TSS Server (check the Update iPhone 4 Baseband setting).
4) Open iTunes, iTunes will prompt you there's a device in DFU mode needed to be restored.
5) Shift+Restore and select the iOS 4.3.3 ISPW file you had downloaded earlier.
6) Wait and should be done without problem.

Congrats bro! Glad it helped!

It's not a must to tick the update baseband box, just that if left unchecked, the restore will ended up infinite recovery loop, and you need to use certain tools to kick out of recovery (I used Fix Recovery at that time)
And after kick out of recovery, I notice my iPhone 4 iOS had upgraded to 4.3.3, but baseband remained at the one used in 4.1, which caused a problem that the signal bar would show 1 bar all the time (due to iOS version and Baseband version mismatch). So I decided to re-restore and update the baseband since my iPhone 4 is officially unlocked.

To get TinyUmbrella, a simple google search would definitely lead you to it's official blog, with download links obviously there. It's not hard to get it without asking from fellow members here, isn't it?

To save SHSH blobs, connect your iDevice and run TinyUmbrella, then select your device and hit Save SHSH. This will allow TU to connect to Apple server and retrieve all currently available SHSH for your device.
For example, currently Apple is signing for iOS4.3.5, iOS5+ (all beta versions), so in the end you'll get the SHSH for iOS4.3.3 and iOS5+. For versions which Apple had already stopped signing, you WILL NOT GET THEIR SHSH.

But there may not be 100% case. One exception is that you had jailbroken your iDevice before, and Cydia had automatically saved SHSH blobs for you without your awareness.
For example, you jailbroke your device on iOS4.1, once open Cydia and it save your iOS4.1 SHSH blob automatically on it's server. Some time later, Apple announce iOS4.x, you once again open Cydia during this time, Cydia then helped you save the new version iOS SHSH automatically. All the saved SHSH blobs on Cydia server can be found like this:

If this is the case for your iDevice, you can:
1) Connect your device to PC and run TinyUmbrella.
2) In TU, go to Advanced tab, check on the option "Request SHSH From Cydia".
3) Hit Save SHSH and all your SHSH on Cydia server should be saved on your local drive.

Can be done on any computer

This post has been edited by huiqing88: Sep 27 2011, 12:22 AM

Yes. Just make sure the required drivers are installed on the PC (which will be automatically installed with iTunes).

Or you can get them here (I extracted from iTunes installer):
Apple Application Support
Apple Mobile Device Support

Yes, as long as you'd installed iTunes, then you don't need to find any drivers. They are installed together with iTunes.
I just give the link for the drivers in case you don't want to install iTunes

Haha nice font isn't it? I like it very much

Just search for BytaFont in Cydia store, download and install it.
After that, search for font QarmicSans in BytaFont, apply it and respring and there you go

*Remember to backup your original font

This post has been edited by huiqing88: Sep 28 2011, 04:49 PM

@CLian,

For the iTunes not starting itself problem, you can try check the option "Open iTunes when this iPhone is connected" in iTunes

This post has been edited by huiqing88: Sep 28 2011, 10:52 PM

Couldn't agree more...
Jailbreakers spent their time trying to jailbreak iOS as soon as they are released
Furthermore they build those jailbreaking tools which make us users able to jailbreak our device more and more easy
And remember one thing, they never ask for a penny from any users who uses their tools