There are a number of potential causes for a smartphone or tablet repeatedly and unpredictably restarting itself. Please follow the steps below to troubleshoot this problem with your Samsung T699.
Download the latest software update
The current software update for the Samsung T699 may fix any bug(s) that are causing the restarts. Follow these steps to download the latest software update for your Samsung T699.
Note: the steps required for your specific device may vary slightly from the following.
Make sure your Samsung T699 first has a WiFi connection and then on your device go to Settings > About Device > Software Update and then touch Update.
Remove the external SD card
If your Samsung T699 contains an external SD card please make sure your device is powered off, remove the external SD card and then power on the device again and see if any further unexpected restarts occur while your external SD card is outside the device.
If your Samsung T699 works fine without the SD card it is very likely the SD card is at fault. Delete all software on the SD card and see if your device works with the SD card after you have wiped it of data. If your smartphone or tablet still restarts unexpectedly while the empty SD card is inside it the SD card likely has a hardware fault and will need to be fixed by an engineer or replaced with a new SD card.
Perform a factory reset
A factory reset will restore your Samsung T699 to the state it was in when it left the factory. This means that all the changes you’ve made to your device and all the media you have stored in its internal memory will be wiped, so please make a backup of anything you don’t wish to lose on another device, such as a PC. When you’ve safely made back ups of all your important data follow these steps. Note: the steps required for your specific device may vary slightly from the following.
Go to Settings > Back up and reset > Factory data reset and then touch Reset device.