Posted by TechGeek on December 29, 2011
Last month, I was using Vodafone 3G micro sim card in my iPhone and everything was working fine for a day or two. Suddenly, I was shocked to see “Sim Failure” message with “Invalid Sim” or “No Service” in the status bar (upper left corner of my iPhone). I tried to re-insert the card couple of times but it was giving me same error messages number of times a day. Even, I bought new micro sim cards from different vendors to check if the issue is with my network provider but found the issue was with iPhone 4S. I was frustrated with this and was looking around on the Google for patch or solution.
I posted the same problem over the apple community and found that Apple has released a tweaked version of iOS 5.0.1 to address this problem. According to Apple, iPhone 4s sometimes fails to detect sim card installed resulting in the following behaviors.
- Invalid SIM” or “No SIM Card installed” alert appears intermittently.
- Status bar displays “No Service” or “Searching” in a location with good network coverage.
The original build number for Apple iOS 5.0.1 is 9A405 whereas the version of tweaked one is 9A406. I have installed that version by carefully taking backup of my iPhone settings. I have tested this for day and two and I have never encountered any error so far. This means Apple addresses this failure issue in that new version which is not released officially rather you can say it as a minor update. I would not say minor as I was having lot of issues with failure of sim like no calls, no internet?.
So if you are an iPhone fan and facing similar issue, you can follow simple steps to update your iPhone iOS to this tweaked version.
1) Connect your iPhone to a computer with iTunes installed.
2) Select the iPhone from Devices menu.
3) Right click on the iPhone and click on Backup. This will backup your iPhone contents and settings to a computer.
4) Restore your iPhone 4S using iTunes by clicking Restore button below the Check for Update button.
5) iTunes will start downloading the new iOS version.
6) Once the download will finish, it will restart your iPhone with newly iOS. iTunes will ask you to restore your backup from computer.
7) Once you restore your backup, you can verify that the version is now iOS 5.0.1 (9A406) in Settings > General > About.
Hope this will help those who are currently suffering from Sim error issues with new iPhone 4S. Here is the direct link to Apple document.