How to activate iPad 2 GSM model after updating to iOS 9.3
If you can’t activate your iPad 2 (GSM model), try these steps.
After you update to iOS 9.3, you might see this message on your iPad 2 (GSM model): “Your iPad could not be activated because the activation service is temporarily unavailable.”
To activate your iPad 2 (GSM model), update it to iOS 9.3 again using iTunes:
- Connect your iPad to a computer. If you don’t have a computer, you can borrow one, or go to an Apple Retail Store or Apple Authorized Service Provider for help.
- Open iTunes. Make sure that you have the latest version of iTunes.
- While your iPad is connected, force it to restart: Press and hold the Sleep/Wake and Home buttons at the same time. Keep holding down the buttons until you see the Recovery mode screen.
- When you get the option to restore or update in iTunes, choose Update.
- iTunes will try to reinstall iOS without erasing your data. If it takes more than 15 minutes, your iPad will exit recovery mode, and you’ll need to repeat steps 2 and 3 again.
- After the update is complete, you need to leave your iPad connected to the computer and complete the activation setup process for your iPad using iTunes.If iTunes doesn’t recognize your iPad after the update is complete, disconnect your iPad and reconnect it to the computer. If it still doesn’t appear, try to connect it to another computer to complete the setup process.
Source is Apple Support.