Upgrading to a new firmware or jailbreaking your current one, it may cause your some problems. Fortunately, developers always find different ways in order to fix our problems and all those errors we encounter when we try to change some things to our iDevices. So, the latest problem users encounter when they jailbreak iOS 5.1.1 with the help of Absinthe, is that they do not have any service on their devices. The No Service issue is quite popular among jailbreakers and many users complain about it. It appears when the jailbreak process is completed and you try to upload the backup plan for your device using iTunes. Since it is an important matter, here you have two solutions that you can try out to see if they work properly for you:
This problem might have its roots in the settings tab and it is related to the network settings. In this respect, here is what you need to do:
Go to Settings App / General / Reset / Reset Network Settings.
This is not that complicated and if you encounter the No Service issue, you should try out this method first. It turned out to be quite successful for some users who complained of this particular problem. In the same time, if this solution does not work, you have another solution.
You can try to replace your current SIM card with another one to see if the problem persists. In this time, you should follow these steps:
1. Restore your firmware once again.
2. Put your device in the DFU mode and start the jailbreaking process once again.
3. Follow the exact steps of the jailbreak process.
Once you are done, you should not use iTunes to restore your backup again. Try to find and use another program such as iTools to restore your back up and to see if you encounter the same problem.