Follow the steps mentioned below until your problem is sorted.
1. Restart Your Android Device
It works 80% of the time. Screen locking/managing applications often make touchscreen unresponsive. In that case you need to restart your Android device. How can I reboot my tablet, the touchscreen is not working.. Good question!
- Grab your Android tablet/phone
- Press and hold the Power Button for 10 seconds or until the screen goes blank.
- Wait a minute or two and then power on your device normally using the same button.
2. Eject Memory Card and Sim
Shutdown your Android device and remove the Memory card and Sim(s) attached to it. Also, remove the battery for few seconds if possible.
3. Remove Any Cases
Smart cases are good in protecting your device from scratches and damage. But their automatic screen wake/sleep feature sometime cause the device to malfunction. Remove the case, perform a restart.
4. Hard Reset your Android
For advanced users.
If everything else doesn't work, try doing a hard reset on your phone. This will wipe your phone/tablet and return it to its original condition. This usually involves holding down Volume-Up and Volume-Down button together and then pressing Power Button (every phone has different method). It starts your device in Recovery mode, you can do a Wipe-Factory-Reset from there. Use volume up/down buttons to navigate and press Power button to select. Be careful and don't mess with other options or you may brick your phone.
5. Knocking the Touchscreen (Not recommended)
Remove the Screen Protector on your Android device if present. Now, gently knock every corner of your touchscreen to realign it. Sometimes continuous phone drops cause screen digitizer cable to loses its connection to device motherboard however, its a rare case.
If you are still unable to make touchscreen work maybe its time to claim warranty, Its a lengthy process but works. Also, post comments below to share other tips not mentioned in this article.