Here are some steps that could help resolve an issue with a device’s screen randomly turning on and off:

1. Check the power source: Make sure the device is plugged into a working power source, and that the cable and plug connections are secure.
2. Check active apps: Make sure none of the active apps are preventing the device from sleeping.
3. Check battery: If the device is low on battery, charge it overnight.
4. Check auto-lock setting: Make sure the auto-lock setting is set a reasonable amount of time, usually a couple of minutes.
5. Restart and reset: Try restarting the device, or resetting the device.
   a) Restart: Hold down the power button for several seconds and select Restart when the menu appears.
   b) Reset: Hold down the power key and the volume down key for 12 seconds. The light on the device should come on, and select the Reset option when the menu appears.