How do I fix an unresponsive touchscreen on a Galaxy device?

Press and hold the Volume Down and Power key for 7 to 10 seconds to perform a forced reboot or soft reset. On phones without a dedicated Power key, press and hold the Volume down key and Side key for 7 to 10 seconds.

The Device care feature will improve your phone's overall performance by scanning for wasted storage space and other potential issues. Navigate to and open Settings. Tap Device care, and then tap Optimize now.

Booting your smartphone in safe mode is also another option to find out if the screen still flickers or not. Safe mode is like a diagnostic tool to help identify the problems on your device.

Step 1: Turn off your device then power on.

Step 2: When the Samsung logo appears by itself, press and hold the Volume down key.

Step 3: The device will switch on in Safe mode. Safe mode will be displayed on the bottom left of the screen.

If the screen works in safe mode, an app is most likely causing your issue. Remove recently downloaded apps one by one until the problem is fixed. If the problem persists when your device is running in Safe mode, the problem might not be related to an app.

To exit safe mode, restart your device

A factory reset, also known as a hard reset or master reset, is an effective, last resort method of troubleshooting for mobile phones. It will restore your phone to its original factory settings, erasing all your data in the process. Because of this, it's important to back up the information before you do a factory reset. 

For step by step instructions on Factory Resetting your device, check out our guide Factory Data Reset a Samsung mobile device or check out our page Backing up my Samsung device for backing up assistance.