how to completely erase and restore iPhone?

devotionfrees

macrumors newbie
Original poster
Jun 1, 2012
6
0
Hi there!

I was coming from Japan to Europe with my Softbank-iPhone 4. I've jailbreaked / unlocked it before and thought that I could do it again without any problems. I got a SIM-card from the telephone shop but then found out that I could not unlock the phone because I already updated to 5.1.1 with an un-lockable bandwidth. Well...

I've organized another iphone now, a 3GS on 5.1. I've put the SIM inside but I can not get it started because the SIM is not compatible. It needs to be jailbroken and then unlocked.

I don't care about the system either, so if there's any possibility to completely erase it, to completely brick it, and put an old system on it and then jailbreak and unlock it (without compatible SIM), that would be great...

Q1: What's the best way to unlock the 3GS?
Q2: Is there any way (I didn't find any) to put an old IOS on the iPhone4 to be able to unlock it?

Thanks for your help!
 

TriJetHero

macrumors 601
Oct 13, 2010
4,953
141
World
Again it depends on the Baseband, anything higher than 05.13.04 on the 3GS cannot be unlocked.

You cannot downgrade the BB.

If it is higher than 05.13.04 and the old bootroom 3GS you can install the ipad 06.15.00 BB but you might loose GPS functionality.

But only on the earlier 3GS. On a new version it can fry your radios.

Besides that downgrading iOS only works if you have proper SHSH/blobs for that device and no BB downgrade possible.
 

devotionfrees

macrumors newbie
Original poster
Jun 1, 2012
6
0
Again it depends on the Baseband, anything higher than 05.13.04 on the 3GS cannot be unlocked.
Thanks for the response!

How do I find out about the BB? The 3GS is in the set-up-mode without a compatible SIM and all I can find is an info-screen telling me about IMEI and ICCID
 

devotionfrees

macrumors newbie
Original poster
Jun 1, 2012
6
0
Settings-General-About-Modem Firmware
Ye, thanks. I know where to find the information on an iPhone that's actually working. But the phone that I have does neither show me any apps nor the settings. It's not activated.

The only message it shows is:

"SIM not valid" (even if there's no SIM inside)

"Only compatible SIM cards from a supported carrier may be used to activate iPhone...etc..."

and a small info-button with IMEI and ICCID

So: what to do?
 

gngan

macrumors 68000
Jan 1, 2009
1,828
72
MacWorld
Hi there!

I was coming from Japan to Europe with my Softbank-iPhone 4. I've jailbreaked / unlocked it before and thought that I could do it again without any problems. I got a SIM-card from the telephone shop but then found out that I could not unlock the phone because I already updated to 5.1.1 with an un-lockable bandwidth. Well...

I've organized another iphone now, a 3GS on 5.1. I've put the SIM inside but I can not get it started because the SIM is not compatible. It needs to be jailbroken and then unlocked.
If you've JB and unlock before then why did you just randomly get a 3GS without knowing your options to jailbreak and unlock?

I don't care about the system either, so if there's any possibility to completely erase it, to completely brick it, and put an old system on it and then jailbreak and unlock it (without compatible SIM), that would be great...
If an electronic is brick then it will not work anymore; therefore you won't be able to put an old system (firmware) on it. Moreover, you can't just put an old system on iOS devices because Apple made security (blobs/SHSH) for it.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.