touch screen not working

@sanjaysankolli it is possibly that this is a software issue. First, I'd try to go with what Samsung recommends, which is basically a soft reset.

• On devices with a Power key: Press and hold the Power key, and then tap Restart. Tap Restart again to restart your device.
• On devices with a Side key: Swipe down from the top of the screen to open the Quick settings panel. Tap the Power icon, and then tap Restart. Tap Restart again to restart your device.

Of course, you could also try a hard reset, but that will delete all of your files, pictures etc. To me that would be the very last thing I'd try.

My gut feeling is that this is a hardware issue. For that you will need to replace the complete display assembly.

Use something like this video as your guide.

Replacement assemblies are readily available online, just make sure that you get one for your specific model (J400F/DS or J400G/DS).

If that still does not resolve your issue, then you are having issues with the circuit board. Let us know what you find you find out.

While you work on your phone, take lots of pictures. Once you are done with it, take those pictures and create a guide for iFixit. That will help the next person that has the same problem as you do. It's easy and fun to create these guides. https://ifixit.com/Guide/new The iFixit community will appreciate this.

Repair is War on Entropy!