the only reason you went to my site is that you are one of the thousands of iphone 3g users who accidentally/intentionally upgraded your FW to 3.1.3 and tried to jailbreak your phone but ended up losing your network, it also took me more than 50 hours of browsing and downloading resources from the web until i desperately lost my hope and tried the jailbreak tool i never expected to jailbreak my phone and works well with the network and WiFi. but i would like to remind you that i haven't tried to jailbreak iPhone 3Gs and you can try it yourself if you want.
now let us start with the jailbreak iPhone "3G" process:
First, Download the following:
1. Firmware 3.1.2
2. Redsn0w 0.9.3
3. Itunes 9
4. Firmware 3.1.3 (you can use it if on the process,you fail to go to DFU)
5. you can download other softwares if required
Second
if you have 3.1.2 as FW and want to upgrade 3.1.3, its up to you. now that you have the files we need, you have to close itunes and
1. start running Redsn0w 0.9.3.
2. redsnow will ask you to select current IPSW for your firmware. with this you will have to browse for the file "iPhone1,2_3.1.2_7D11_Restore"
3. redwnow will check the file
4. click "NEXT"
5. check "install cydia" ONLY!
6. turn-off your iPhone 3g FW 3.1.3
7. if you already turned-off your phone prepare for DFU mode as you click next and follow the DFU mode instruction from redsnow.
8. once you successfully made the DFU, redsnow will process the iphone and wait for the iphone to finish the jailbreak for you.
9. when the iphone rebooted, check your phone if you have cydia installed.
10. if successful with the jailbreak, check your network. it should work well with your network signal.
11. start itunes and restore your back up. from there you will see that your iphone is running on 3.1.3 firmware and would run smoother than your usual 3.1.2 jailbroken iphone.
Note:
if your fail to go to DFU mode, you can restart your phone or you will have to restore it again to the normal 3.1.3 FW using your itunes and then start the process again. i am not sure if this will also unlock your phone simcard but cydia has all the resources we need to unlock the phone once jail broken,
hope it will work for your iphone 3G.
Here are the links for the files:
Iphone FW 3.1.2 - http://www.quickpwn.com/2009/10/iphone-312-download-links.html
Iphone FW 3.1.2 - http://www.quickpwn.com/2009/10/iphone-312-download-links.html
Redsnow 0.9.3 for windows - http://iphwn.org/redsn0w-win_0.9.3.zip
Redsnow 0.9.3 for mac - http://iphwn.org/redsn0w-mac_0.9.3.zip
Itunes 9- http://www.apple.com/itunes/download
Iphone FW 3.1.3 - download via iTunes
Have fun with your jailbroken phone.