The most common cause why you are facing iPhone no service after jailbreak 6.1.3/5.1.1/ 7 is incorrect Baseband.
No Service error can only be resolved by downgrading your current iPad baseband. Most people jailbreak their iPhone with Redsn0w and upgrade to iPad baseband. And then they use UltraSn0w to activate their service, but fails.
The iPad baseband causes conflict with network service and interferes with the radio Frequency of the device. To successfully get service on your iPhone, follow the procedure explained below.
How to fix iPhone No Service After Jailbreak
- First Download the latest version of RedSn0w
- Download your Firmware here (6.0.1)
- After you have downloaded RedSn0w, Extract and Open it as an administrator
- When Redsn0w is opened, navigate to extra and ‘select ISPW’ and browse for the firmware you just downloaded
- After the process is completed, kernels and Ram had been added. A screen with options will appear.
Visit our Apple Troubleshooting guides
Check to see if you have the iPad BaseBand downgraded:
- Navigate to Settings>general> about
- Check Install Cydia and downgrade From IPad Baseband.
- After that, your iPhone will reboot
- Launch Cydia on your iPhone
- Click on Manage tab at the bottom right
- Select Launch Source
You may read- Jailbreak And Unlock iPhone 3GS 4.1 Baseband 05. 14. 02
- To fix iPhone No Service After Jailbreak –click add at the top left and type http://repo666.ultrasn0w.com/ as the source URL and press the Add Source button.
- Select Return to Cydia
- Select Done at the top right
- Click http://repo666.ultrasn0w.com/ from the source list
- Install and confirm to fix iPhone No Service After Jailbreak
- The final step is to restart Springboard and now you can place your SIM card within your iPhone 4/3Gs/4s/5/3 and you shall get Service.
If this method did not solve the service error after you have jailbroken your phone and downgraded your iPad baseband, then try this one. Be sure to back up all data by iCloud or computer.
Insert your SIM card that is receiving no service error and head over to Settings > General > Reset > Reset Network Settings.
You should also read –How to fix stuck on the slide for emergency and connect to iTunes screen.