Depending on what type of Touch Screen phone you have, here’s how you would fix them:


 

Android

  1. Turning off Phone completely for 15 seconds.
  2. If your device allows you to do so, physically remove your battery from the device. If not, then use the built-in function that “simulates” what’s known as a “Battery Pull”. Both must be done while the Phone is still powered “On”. After one minute, reboot your device.
  3. Boot your cell phone into “Safe Mode”.
  4. Install Anti-Malware Software Apps.
  5. You Must Back-Up as much of Your Data as possible and Do as much Research as possible. After both tasks are completed, Do a Factory Reset before re-installing each application to see what caused the problem.
  6. Buy a Replacement Touchscreen.

iPhone

  1. If you have a case or screen protector on your phone, (try to) remove it.
  2. Clean your screen with a soft, slightly damp, lint-free cloth.
  3. Unplug your device.
  4. Turn off and Restart your Device.
  5. Contact Apple Support.
  6. Take your device to either an Apple Retail Store or an authorized Apple Service Provider.

Honestly the best way is to download and install a 3rd party app that can test the screen.. both the touch screen and screen colors. Most Android phones have a diagnostic mode you can enter by typing in *#*#0*#*#* in the phone dialer (it’s an LCD display test) BUT a lot of cellphone carriers have been BLOCKING the diagnostic mode for some weird reason.. I know Verizon does and my T-Mobile phone doesn’t let me access it… that’s why I said it’s best to download and install a 3rd party app from the app store that can perform a screen diagnostic test (just type in screen diagnostic test in the app store). If the screen is already broken, then there’s no point in using the test and you need to replace the screen.

The technical reason would be that the touch sensor stopped sending data to the motherboard, not registering your touch.

Let’s go a bit deeper.

Here the problem could be anything-

  1. Faulty pin on motherboard.
  2. Sensor not working.
  3. Motherboard not working
  4. Faculty pin on sensor connector.
  5. Software issues (several more!).
  6. Cable not working (broken or bent).
  7. Issues with power supply.
  8. Faultt battery.

These are just to name a few. There may be many other reasons, or a combination of those that lead to a touchscreen not responding to touch.