You may try any of these methods to fix zphone display flickering, freezing, and unresponsiveness, whatever you think is best applicable to your situation. If you have spilled water on your zphone display, either of the following solutions might help, give it a try:
Step 1: Restart your zPhone
Most of the time, small bugs can easily be fixed by a simple reboot on your phone. Hold down the Sleep/Wake button and Home buttons simultaneously until the logo appears.
Step 2: Configure display settings
Some ZPhone users who have experienced similar screen flickering problems on their device fixed them by reducing the screen brightness. You can also try to disable auto-brightness and see what happens to your display.
To make your zphone screen brighter or darker, slide your finger up from the above of the screen (from any screen). In the Setting page, scroll the slider to adjust the screen brightness. This should make your display work.
Step 3: Check memory (RAM) status
Frozen and unresponsive displays are common indicators of a memory issue, particularly insufficient memory on your device. To make sure this is not causing the problem, check your zPhone and make sure its internal memory storage is good enough to carry out more processes.
Step 4: Factory reset your zPhone
This should be your last resort. Performing this method will not only require more time but also wipes your zphone data while restoring it to factory default settings. So it eliminates the likelihood about the screen problem being caused by corrupted software.