New iOS 5.0.1 Build 9A406 Intended to Fix 'No SIM Card' Errors on iPhone 4S

Yesterday, we noted that Apple had quietly released a tweaked version of iOS 5.0.1. The purpose of the tweak was a mystery given that the update was not being pushed to all users and only made available to those newly updating to iOS 5.0.1. The new version arrived as Build 9A406, and increment of one over the original iOS 5.0.1 release.

But based on a new Apple support document, it now appears that the updated build may have been designed to address an issue some users have been experiencing with SIM card-related errors. With the update affecting a relatively small portion of users, Apple may have elected not to push it out to all users in the form of an iOS 5.0.2 software update, and instead rely on those users who are having problems following Apple's advice and obtaining the new build through the restore process outlined as a solution for the issue.

no sim card installed
Last month, some attention was turned on Apple as a quickly-growing thread in Apple's discussion forums revealed a number of users experiencing problems with either a "No Service" or "No SIM Card Installed" warning popping up on their iPhone 4S devices. From Apple's new support document:

In certain situations, iPhone 4S may have difficulty recognizing a micro-SIM card, 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.

Apple goes on to describe the recommended solution for the issue, which involves backing up and then restoring the device, an action that involves iTunes pulling down the new Build 9A406 of iOS 5.0.1 and installing it on the user's device. Once the device's system has been restored, the user can then restore content and settings from a backup.

1. Back up your user content and settings using iTunes or iCloud. See this article for more information.
2. Restore your iPhone 4S using iTunes.
3. After the process is complete, restore your user content and settings from your backup.
4. To confirm that you've successfully restored, verify that the version is now iOS 5.0.1 (9A406) in Settings > General > About.

Unfortunately, user reports on the new build appear to be mixed, with some users reporting that it does indeed fix their "no SIM card" issues while others have seen no improvement. It is unclear at this time exactly why results are mixed and whether the fix addresses only some subset of the root causes of the issue or if some other factor is in play. Consequently, we may have to wait for more users to try applying the update before drawing more specific conclusions.

Related Forum: iPhone

Popular Stories

iOS 26

iOS 26.4 and iOS 27 Features Revealed in New Leak

Friday December 12, 2025 10:56 am PST by
Macworld's Filipe Espósito today revealed a handful of features that Apple is allegedly planning for iOS 26.4, iOS 27, and even iOS 28. The report said the features are referenced within the code for a leaked internal build of iOS 26 that is not meant to be seen by the public. However, it appears that Espósito and/or his sources managed to gain access to it, providing us with a sneak peek...
iOS 26

iOS 26.2 Coming Soon With These 8 New Features on Your iPhone

Thursday December 11, 2025 8:49 am PST by
Apple seeded the second iOS 26.2 Release Candidate to developers earlier this week, meaning the update will be released to the general public very soon. Apple confirmed iOS 26.2 would be released in December, but it did not provide a specific date. We expect the update to be released by early next week. iOS 26.2 includes a handful of new features and changes on the iPhone, such as a new...
iOS 26

Apple Releases iOS 26.2 With Alarms for Reminders, Lock Screen Changes, Enhanced Safety Alerts and More

Friday December 12, 2025 10:10 am PST by
Apple today released iOS 26.2, the second major update to the iOS 26 operating system that came out in September, iOS 26.2 comes a little over a month after iOS 26.1 launched. ‌iOS 26‌.2 is compatible with the ‌iPhone‌ 11 series and later, as well as the second-generation ‌iPhone‌ SE. The new software can be downloaded on eligible iPhones over-the-air by going to Settings >...
AirPods Pro Firmware Feature

Apple Releases New Firmware for AirPods Pro 2 and AirPods Pro 3

Thursday December 11, 2025 11:28 am PST by
Apple today released new firmware designed for the AirPods Pro 3 and the prior-generation AirPods Pro 2. The AirPods Pro 3 firmware is 8B30, up from 8B25, while the AirPods Pro 2 firmware is 8B28, up from 8B21. There's no word on what's include in the updated firmware, but the AirPods Pro 2 and AirPods Pro 3 are getting expanded support for Live Translation in the European Union in iOS...
macOS Tahoe 26 Thumb

Apple Releases macOS Tahoe 26.2 With Edge Light

Friday December 12, 2025 10:08 am PST by
Apple today released macOS Tahoe 26.2, the second major update to the macOS Tahoe operating system that came out in September. macOS Tahoe 26.2 comes five weeks after Apple released macOS Tahoe 26.1. Mac users can download the macOS Tahoe update by using the Software Update section of System Settings. macOS Tahoe 26.2 includes Edge Light, a feature that illuminates your face with soft...
AirTag 2 Mock Feature

Apple AirTag 2: Four New Features Found in iOS 26 Code

Thursday December 11, 2025 10:31 am PST by
The AirTag 2 will include a handful of new features that will improve tracking capabilities, according to a new report from Macworld. The site says that it was able to access an internal build of iOS 26, which includes references to multiple unreleased products. Here's what's supposedly coming: An improved pairing process, though no details were provided. AirTag pairing is already...
ipados 26 1 slide over

Apple Releases iPadOS 26.2 With Multitasking Improvements

Friday December 12, 2025 10:09 am PST by
Apple today released iPadOS 26.2, the second major update to the iPadOS 26 operating system released in September. iPadOS 26.2 comes a month after iPadOS 26.1. The new software can be downloaded on eligible iPads over-the-air by going to Settings > General > Software Update. iPadOS 26.2 continues with the multitasking improvements that were added with iPadOS 26.1. You can now drag and...
bug security vulnerability issue fix larry

Update Now: iOS 26.2 Fixes 20+ Security Vulnerabilities

Friday December 12, 2025 11:11 am PST by
Apple today released iOS 26.2, iPadOS 26.2, and macOS 26.2, all of which introduce new features, bug fixes, and security improvements. Apple says that the updates address over 20 vulnerabilities, including two bugs that are known to have been actively exploited. There are a pair of WebKit vulnerabilities that could allow maliciously crafted web content to execute code or cause memory...

Top Rated Comments

mms13 Avatar
183 months ago
Just give me 5.1 and please make my battery better.
Score: 6 Votes (Like | Disagree)
pizzafootbal Avatar
183 months ago
Now why wouldn't Apple release 5.0.1.1 or 5.0.2?
Score: 3 Votes (Like | Disagree)
PurrBall Avatar
183 months ago
If you're still having the problem, just go to your carrier and get a new SIM. Worked for me.
Score: 2 Votes (Like | Disagree)
Piggie Avatar
183 months ago
Jeez, how can one company have so many problems with just one phone.

Can you imagine the mess they'd be in if they had 20 or 30 phones they had to support!

Amazing.
Score: 2 Votes (Like | Disagree)
bjeff6 Avatar
183 months ago
RE: Battery

I don't know about anyone else's experiences with this whole issue is but I had VERY POOR battery issues with the 1st iPhone 4S I purchased and no matter what nothing could/would fix it. Second iPhone 4S, better battery but still lacking on iOS 5.0 and 5.01. I am now finally seeing OUTSTANDING battery life on iOS 5.0.1 9A406. I had tried the developer releases (both of them) but neither helped with poor battery issues... I choose to roll back to iOS 5.0.1 9A405 until this new release came out, oddly it was about 50MB smaller than 9A405, I suspect it is missing the Carrier IQ stuff... Just a guess though

Of course, YMMV so take it for what it's worth but I am still on 100% battery with light usage (checked email and loaded Facebook) with about 4 hours standby included... Very pleased

:)
Score: 2 Votes (Like | Disagree)
garylapointe Avatar
183 months ago
Delta Updates?

I thought one feature of the new iOS was to be able to do minor incremental updates and not have to do major updates...

That should make something like this relatively minor. And it should have a new number if there are changes, you shouldn't have to know the version and the 4 digit hex code. 5.0.1b would work just fine....

Gary
Score: 1 Votes (Like | Disagree)