Off topic: c.doogee.cc says: Can't start discussion. So I describe my problem as an answer here.
I have a S40pro smartphone over 1 month.
Problem: no sound (not in speaker, not in earphone).
I don't use it as a phone, I only use it for navigation.
Navigation: Magic Earth or OsmAnd when driving a car (voice is important),
OsmAnd for outdoor (without voice).
I can use both offline.
Connection: WLAN for downloading new maps.
Testing videos by WLAN: no voice, deadly silent.
What I did: I activated all sound options, but this did not help.
What I did: I uninstalled some newer apps, but this did not help.
From Google Play I installed "Phone Doctor Plus", this tool shows a red "X" what means that the speakers cannot be tested.
What must I do?
Thx in advance for your hints.