Fix Lumia 640 Keeps Rebooting Randomly
Method 1: Install the latest updates on the device Simply installing the latest updates on your Lumia 640 can improve its stability and also introduce patches designed to get rid of the random reboot bug to the device. To check for updates on your Lumia 640: Go to Settings. Tap on Phone Update. Tap on Check for Updates and allow the device to check for the latest updates and inform you of any that exist....