Default [Q] audio problem

Hello to all!
I had bought XT720 and I have audio problem.
My phone wont ring (or play any MP3 file, or even phone ringtone in settings menu)

But what is interesting, when I call someone, and put that person on loudspeaker, I can hear person.
Same thing is happening with FM radio - when I select loudspeaker option, FM station is heard on speaker

If I put headphones, it's the same...can't hear anything, except FM radio and when I'm on phone

I installed froyo, bravo and stock rom, and on all is same problem...

can anyone help me?
thx