Hi,

I have a 4.01 3GS that is giving me lots of problems and I want to upgrade it to 4.02 to see if it will fix it. Can I still jailbreak and unlock? I see a lot of people wanting to downgrade, why is that?

Thanks,

Originally Posted by edwinx

Hi,

I have a 4.01 3GS that is giving me lots of problems and I want to upgrade it to 4.02 to see if it will fix it. Can I still jailbreak and unlock? I see a lot of people wanting to downgrade, why is that?

Depends.. Upgrade - no, restore with custom ipsw - maybe

New bootrom 3GS - NO
Old bootrom 3GS, jailbroken with jailbreakme - difficult
Old bootrom 3GS, jailbroken with pwnagetool - yes but not a good idea

Problem... you need to use pwnagetool to do this. There are no official pwnagetool bundles for 4.0.1, 4.0.2 or 4.1 (yet). The bundles that are floating around are incomplete - they don't include all the required patches. This especially affects syncing of iBooks and also some Cydia apps (especially those that hook into the OS at a low level)

There is no way to directly jailbreak 4.0.2 (if it could be jailbroken, unlock would work)
There is no way to directly jailbreak 4.1 (if it could be jailbroken, unlock would NOT work due to updated baseband)

There is no way to upgrade to iOS 4.0.2 (original IPSW) unless you already backed up your 4.0.2 SHSH as Apple has stopped signing everything except 4.1 now.

Ok, my 3gs was jailbroken using jailbreakme. my modem fw is 5.13.04, that is the newer one right?

ok, how bout just restoring 4.01 on it it and then jailbreaking it?

The reason why I want to do this is because my phone's radio is turning off every now and then. Everynow and then, I would lose all reception, then after 5-6 seconds, it would come back. Its annoying since I would miss calls while my phone is in sleep more and I am in good reception area too, no reason to drop signal like that. I was hoping a restore would fix it.

Originally Posted by edwinx

Ok, my 3gs was jailbroken using jailbreakme. my modem fw is 5.13.04, that is the newer one right?

ok, how bout just restoring 4.01 on it it and then jailbreaking it?

The reason why I want to do this is because my phone's radio is turning off every now and then. Everynow and then, I would lose all reception, then after 5-6 seconds, it would come back. Its annoying since I would miss calls while my phone is in sleep more and I am in good reception area too, no reason to drop signal like that. I was hoping a restore would fix it.

Modem firmware has nothing to do with whether or not you can jailbreak.

Jailbreakme is not a low level jailbreak. This means you cannot bypass the SHSH checks that are made when you try and restore an ipsw. Right now Apple only signs SHSH for restore of 4.1.

If you backed your shsh for 4.0 or 4.0.1 you can use tiny umbrella to restore 4.0 or 4.0.1 with the cached SHSH and then jailbreak again with jailbreakme. Otherwise you have no chance.

I have backed up my shsh using tinyumbrella. I guess I need to search on how to it to assist me in restoring 4.01 onto my phone.

sorry, I thought modem fw was another name for bootrom...

thanks for your replies.

1 more question. Can I upgrade to 4.1 via itunes and downgrade back to 4.01? I have saved the SHSH checks at 4.01 using tinyumbrella.

Originally Posted by edwinx

1 more question. Can I upgrade to 4.1 via itunes and downgrade back to 4.01? I have saved the SHSH checks at 4.01 using tinyumbrella.

Only if you want to lose your option to unlock.

The only way to stop your baseband being updated is to use pwnagetool (old bootrom only) to restore custom 4.1

Restoring or updating original (unmodified) 4.1 will always update baseband and there is no unlock for the baseband that is included with 4.1