Final answer:
Rebooting the device, updating device firmware, and checking for software updates are actions that may help when troubleshooting a non-responsive touchscreen on a mobile device.
Step-by-step explanation:
When troubleshooting a non-responsive touchscreen on a mobile device, there are several actions you can take. First, rebooting the device can often resolve temporary software glitches and restore normal functioning. Second, updating the device firmware can provide bug fixes and improvements that may address issues with the touchscreen. Lastly, checking for software updates can ensure that the operating system and apps are up to date, which may include fixes for touchscreen problems.