Why does my Nokia 635 vibrate once then returns to the Windows start-up screen?

[Windows Central Question]

Nokia 635 vibrates once then returns to Windows start-up screen

I got my Nokia Lumia 635 in March 2015 and it was working fine until recently. It randomly vibrates once and then blacks out to the Windows logo screen. It also shows the flight symbol at the top for few seconds before blacking out. A few seconds later it returns to my personalized screen. When this happens, my phone calls get dropped and it's really annoying!!!
Any advice, anyone?
Thanks.

 

[realwarder]

Re: Nokia 635 vibrates once then returns to Windows start-up screen

I would re-flash the firmware using Lumia Recovery Tool after doing a backup. If that does not help it sounds like a random hardware fault where the baseband chip is not behaving as expected which will require a support call to fix (repair/replace).

 

[RumoredNow]

Re: Nokia 635 vibrates once then returns to Windows start-up screen

It sounds like you have Random Reboots.

Check for an update. Microsoft is pushing a patch for that.