Yesterday was nagivating, when I touch the screen to activate an app, the touchscreen freeze, well I resetted the cellphone a lot of time but still stuck, and also reset to factory settings and wipe data, not working, finally hours later of search I found the issue the digitizer, is the responsible for touch reactions of the screen, located in the superior left corner, the only thing you do is press for 5 seconds in that area and the sreen working right again, I hope so this thread helps a many persons with this trouble.