Backup, update, restore - question

[sirius]

If I backup my iPhone, then do a factory reset/update, then restore from the backup, will it revert the OS to the previous version (from when I backed it up)?

 

[sirius]

Sorry, meant to add that I've got a 3GS with iPhone OS 3.1.2.

 

[sirius]

Ugh, I'm spamming my own thread, but I wanted to clarify something...

I took my phone in to the Apple store to troubleshoot a weak WiFi issue (poor signal, compared to another iPhone right next to it). They suggested I do a restore and see if that fixed it, otherwise they could replace the phone.

Now, I've been considering jailbreaking it, so didn't want to upgrade to 3.1.3 just yet... if I click the "Restore" button in iTunes, will that automatically upgrade to the current version (3.1.3), or will it put the iPhone back at 3.1 or 3.1.2 or whatever it was when new (I forget what it was)? If it DOES put 3.1.3 on it, can I get back to 3.1.2 by restoring from the backup?

Hope that makes things clearer, thanks.

 

[Alli]

Clicking Restore won't install 3.1.3. There is no way to get back to 3.1.2 once you're on 3.1.3.

 

[sirius]

Thanks for the response Alli. I've reset the phone to 'as new' and am setting it up now.

I've been researching the technical stuff for upgrading and downgrading and jailbreaking, and found I missed the chance to back up my ECID SHSH by 2 days. Just my luck that I finally have time and incentive to do this now... :-(

 

[ElectricDoodie]

I missed it by one day. ONE DAY!

I'm now stuck with 3.1, because they stopped signing off on 3.1.2, a day before I went to go jailbreak my phone.