Blackberry z10-stl 100-1 ringtone not working

hello, I have a bb z10 stl 100-1 model, One day all of a sudden ringtone stopped working, I restarted the phone, removed battery several times, it started working again after several attempts, then again it stopped, I resetted my phone and again it started working. After some one day it is gone again, I updated to 10.3.0.442 version, still no luck its not working, now I am resetting the software and going back to 10.0.10.263 version, I dont know what will happen. Can anyone help me with this. its not a hardware issue. Something related with Software, phone has newer fell down from my hand

Try reloading your OS to the latest 10.2.1 and see how it goes.

Cave, cave, moderator videt