I just had a brand new c5 ultra and ı am having this speaker problem. When I play music with the phone, everything is just fine. But when I try to put my phone calls on speaker(on viber,skype,whatsapp) there is a very strange, loud, whistling sound is coming from the phone. I tried some solutions from the things ı saw on internet, there was no success. I reset the phone to factory settings, nothing has changed.
So please help me or I have to send my phone to warranty
warranty.
