Questions from someone new to Jailbreaking (Iphone 3GS 4.2.1)

[MrR82]

Hi all:

I'm trying to jailbreak and unlock an iPhone 3GS. It will be used on Tmobile so the unlock is necessary.

Info:
iPhone 3GS 4.2.1 (8C148a)
baseband 6.15.00
I believe it is a new bootrom

I have attempted to jailbreak using redsnow 0.9.6b6. However, after cydia installs, it has a white icon box and doesn't load.

Is it possible for me to jailbreak unlock this phone as it currently stands?
If not, do I need to downgrade to 4.XXX?

Thanks in advance.

[Simon]

You need to use redsnow to boot tethered

[MrR82]

I'll give that a try.

Should I start over? Meaning should I restore the iPhone and then boot tethered or is it ok just to go straight to redsnow and boot tethered?

[iYeow]

Just straight tether boot, use redsn0w 0.9.6rc7

[Brandonii]

I have a question. Will the unlock work if you don't boot tethered? I am not sure how this works.
Also, will other cydia apps work if you don't boot tethered? Or if i restart my phone, and am away from my house, i can't use my phone.

[MrR82]

So I was able to load Cydia and go through the unlocking process.
(iClarified - iPhone - How to Unlock the iPhone 4, 3GS, 3G Using UltraSn0w)

Now, after I hit reboot device, I am stuck at the boot up screen with the apple logo. Sigh, just when I thought I was home free.

Do I need to start over with the custom .ipsw -> restore -> jailbreak -> unlock? What did I do wrong?

[Simon]

No it wont work without booting tethered, nothing jailbreak related will work.

So I was able to load Cydia and go through the unlocking process.
(iClarified - iPhone - How to Unlock the iPhone 4, 3GS, 3G Using UltraSn0w)

Now, after I hit reboot device, I am stuck at the boot up screen with the apple logo. Sigh, just when I thought I was home free.

Do I need to start over with the custom .ipsw -> restore -> jailbreak -> unlock? What did I do wrong?

You need to boot tethered again. This is the nature of a tethered jailbreak, every time you reboot it must be done.

[iYeow]

I have a question. Will the unlock work if you don't boot tethered? I am not sure how this works.
Also, will other cydia apps work if you don't boot tethered? Or if i restart my phone, and am away from my house, i can't use my phone.

If you have a tethered jailbreak and you power down and up again, if you don't tether boot, you can't access anything, it will be in recovery mode.

[MrR82]

If you have a tethered jailbreak and you power down and up again, if you don't tether boot, you can access anything, it will be in recovery mode.

So when Cydia wants me to reboot my device, I say yes. Allow it to get stuck. Then I load up redsnow, use a new .ipsw file and reboot tethered?

[Simon]

yup

[iYeow]

It is not that you want it to get stuck, this is the nature of tether boot.

[MrR82]

I will have nightmares about the term tether boot tonight. Trying it out now. Thanks fellas.

NVM

[iYeow]

Yeah, a bad dream about tether boot all night long

[MrR82]

Alright, I'm all set. Once my girlfriend gets home I am going to put in her Tmobile SIM, pray, and then have a drink if it works. I appreciate all the help. Warning - I may come back.

[iYeow]

Make sure you have install Ultrasn0w and turn off the 3g to get T-mobile to work, otherwise you will not enjoy your beer.

[MrR82]

Thanks for letting me know that. I've installed ultrasnow and turned off 3G.

Is this something that is permanent or just with 4.2.1? This phone is for my girl - her last 3GS broke on NYE. But that was an older phone.

I'm wondering if it would make more sense to downgrade (if possible) so she can use 3G and won't by mistake reboot.

[iYeow]

You can downgrade to 3.1.3 if you want but you will still need ultrasn0w to unlock. T-mobile users on iphone have to turn off 3g to make it work.