Your phone shuts down by itself or reboots in a loop
Make sure the power button doesn’t remain pressed
If your phone’s power button remains pressed, it could shut down your phone, or be the reason it reboots in a loop.
The issue could be caused by a protective case (or any other equipment of that nature) that applies pressure on the button without your knowledge.
Charge your battery completely
When the phone cannot store enough charge, it could reboot in a loop or shut down.
Check that this is not an issue with a damaged electric cable. Test with another cable to make sure.
You can also test the charge by removing the power supply block, and connecting the USB end (Type A) into a compatible device.
Check that the cable works well by trying to charge another phone if you have one.
Restore your phone to its factory settings
IMPORTANT: Save all media, contacts, apps and text messages that are archived and want to keep before proceeding.
Some of your phone’s parameters will need to be reconfigured after: mobile data blocking, NPA, Wi-Fi settings, Bluetooth function etc.
The steps to follow to reset your network settings will vary depending on the type of phone. Here are two examples:
Android: Applications → Settings → General management → Reset → Reset settings → Click on Reset settings
iPhone: Settings → General → Reset → Erase all content and settings
Check whether the issue is still there before configuring and personalizing your phone, or installing apps.