Q: No cellular service after ios8 update

Have you tried powering off, and then back on again, with the power button (not home button)?

YEs. Tried that. It works and when the iPad locks again or goes to sleep it's back to no service. Checked in general about and after reboot it knows the ipad cellular number from att. When it says no  service the number says unknown. Something is broken. I can reboot before I need it but to have to reboot to use it that's annoying and bad. I even reset my network settings on iPad overalL. Works until next lock/sleep and then back to no service.

Well, at that point, I would be heading down to the Apple Store to talk to a "Genius" ... :-) ...

Of course there are a few other time consuming things to do, but I would personally prefer going to the Apple Store.

Mine is from work. So I'll have to tell them. Of course they will say I should not have updated yet.  So I'll have to wait for an apple fix.

I have the same problem with my iPad 2.  I went to Genius bar, they ran diagnostics and told me it was an "impending" hardware failure an that the upgrade to ios 8 had cause it to lose it's settings.   basically blaming it on the hardware and not the software.  I am having a hard time believing this.

Loss of cellular service or ability to use Touch ID after updating to iOS 8.0.1 on iPhone 6 or iPhone 6 Plus

To follow up on this, I was able to downgrade my IOS to 7.1.2 and my cellular service was restored.  Apple's tech support at the store mis-diagnosed the problem or deliberately lied about it.  It is beginning to sound like Microsoft all over again :-(  Apple should allow downgrades, especially with their OS breaks the hardware, OR, consider the hardware end of life and prevent future OS upgrades if no longer supported.  This lack of transparency and information is disturbing to me given that they told me my only recourse was to buy a new iPad.

Download new software update 8.0.2 that should help you. Bsydd uk

I would not install 8.0.2 unless Apple admits that this update specifically addresses this issue.  Apple states that if fixes an issue with 8.0.1, which was pulled for the bug.  Nothing was ever mentioned about this bug in 8.0.  

iOS 8.0.2 is now available for users, it fixes an issue that affected iPhone 6 and iPhone 6 Plus users who downloaded iOS 8.0.1, and includes improvements and bug fixes originally in iOS 8.0.1. We apologize for inconveniencing the iPhone 6 and iPhone 6 Plus users who were impacted by the bug in iOS 8.0.1.

Not mentioned to fix the problem with iPad 2 image.

IOS 8.0.2 RELEASE NOTES

This release contains improvements and bug fixes, including:

• Fixes an issue in iOS 8.0.1 that impacted cellular network connectivity and Touch ID on iPhone 6 and iPhone 6 Plus
• Fixes a bug so HealthKit apps can now be made available on the App Store
• Addresses an issue where 3rd party keyboards could become deselected when a user enters their passcode
• Fixes an issue that prevented some apps from accessing photos from the Photo Library
• Demonstrates the awesomeness of OSXDaily.com by inserting silly comments into the release notes of iOS
• Improves the reliability of the Reachability feature on iPhone 6 and iPhone 6 Plus
• Fixes an issue that could cause unexpected cellular data usage when receiving SMS/MMS messages
• Better support of Ask To Buy for Family Sharing for In-App Purchases
• Fixes an issue where ringtones were sometimes not restored from iCloud backups
• Fixes a bug that prevented uploading photos and videos from Safari

I have installed 8.0.2 last night and the issue still exists. I am on an ipad2 I have ATT and 3G works fine. After a long time of inactivity and the ipad goes to sleep when it waked up it says no service and the only way to get 3g back is to hard reboot. I have tried turning off and on cellular and restoring network settings. I do NOT want to set it up as a new device unless I KNOW for sure that it will fix the issue as I do not want to lose my saved progress on kids games and apps etc...I can do it of course but only as a last resort. Hopefully others experience this as well enough so Apple addresses it or someone else comes up with a fix as well.

You can set it up as a new device just to see if it resolves the issue.

If it does not then restore again from your backup, let Apple know here and wait for an update.

If it does the the problem exists in your backup.

Good point. I can try that this weekend.

Try this Download new iOS 8.0.2 out today may fix some problems. Bsydd uk