I can't disable airplane mode on my Lumia 620. When I turn it off, in less than one second, it turns back on. What should I do?
Follow these steps to resolve this airplane mode issue:
Download the Windows Device Recovery Tool
Once installed, Open the tool
When it notifies, connect your phone
It checks for the latest update for your phone.
Click install (or reinstall if there is no update). The update gets downloaded into your PC then it will be installed
The update will be around 1.5 Gb, you can disconnect your phone once the download starts. You need to reconnect it once the download is completed.
Then click install.
A big thing here is that the download size pretty large and the max speed would be around 200 kb (approx), even though you use high-speed internet connection.
One more thing: don't panic, your phone may restart few times during the installation process. Most probably it may take 20-25 mins for installation.