Iphone 3G jailbroken/unlocked on 4.2.1 Problem

[Antoto]

Hi all. I have a problem. I paid someone $15 to jailbrake and unlock my 3g but to my surprise he updated my phone to 4.2.1 and 6.15 baseband and I hate it big time, phone is slow as hell. My question is how can I go back to 3.1.3 and baseband 5.15.04 or go back to a faster OS version and of course be able to easily jailbrake and unlock it on my own. Hoping some of you experts out there can guide me step by step how to do it. Help!

Thanks! -Nick

 

[Ipheuria]

Well it's too bad you didn't come here first you just paid someone to do something you could have done yourself. Anyway do you use a Mac or Windows? Do you have stuff on the phone you care about? I can help you but not sure if you'll be able to downgrade yet. The baseband can't be downgraded and that baseband is unlockable anyway so I wouldn't worry about the baseband. Go into Cydia and look at the top and see which firmware shows along the top and post that here for us. You should also ge Tiny Umbrella.

 

[Antoto]

Great. I have a Windows 7 based PC, and the Iphone is currently on 4.2.1 and downloaded "Tiny Umbrella" to my desktop and lastly I don't have any thing in the phone worth keeping. -Nick

 

[Ipheuria]

OK so go into Cydia and tell me what firmware it lists right across the top. This will tell us if there are any SHSH blobs backed up for the phone that you might be able to downgrade.

Go here Sn0wBreeze | iPhoneHeat and look for the Sn0wbreeze that worked with 3.1.3

Go here iClarified - iPhone - Where To Download iPhone Firmware Files From and get the 3.1.3 firmware.

Follow the Sn0wbreeze tutorial except put it in Expert mode not Normal mode. Make sure you have "Activate the phone" checked. Create your custom ipsw and have it ready. Once you let me know if you have any SHSH blobs saved we'll go from there

When you're all done follow below

Unlock
iClarified - Tutorials - iPhone and go to Unlock follow the steps.

 

[Antoto]

Hello. Sorry to get back to you just now. I decided to ask the guy that charged me $15 bucks to downgrade it to 3.1.3 unlocked! and I'm happy to report he successfully did it. Based on this experience, I would recommend any one on this forum to never upgrade to OS4 and above. 3G phones are not meant to run this software specially if jailbroken. Going forward, can I reach to you to guide me how to jailbreake-unlock an Iphone 3G on 3.1.3 based band 5.15.04? Chances are I will be buying another phone soon. I will post my question on this forum once I get the new phone. Thanks a lot once again for your volunteering to walk me thru.

BTW, I'm from the San Francisco Bay Area.
-Nick