Screen touch sometimes not working

@forno intermittent errors like this are hardest to diagnose. It could be a firmware issue. I would reset my phone first, if that does not help do a hard reset. You NEED to have all of your files,, pictures, password etc. backed up because a hard reset will delete those files. You can always check on here for the how-to.

If that does not fix your phone, it'll be the touch screen itself. Replacing it might be a solution. You will need to replace the complete display assembly since the touch screen is part of that. Use something like this video as your guide

If that still won't work, it is time to do some checks on the board. Use the Flowchart for that

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!