HDD CONNECTED TO TV, GET SOUND FROM AVR ??

[MANINDIA]

Hi
I have an Airtel STB + Onkyo AVR + Samsung TV.
My current connection is :
Airtel (HDMI out) to TV (HDMI In)
AVR (HDMI out) to TV (HDMI In)
Airtel (optical cable) to AVR (optical cable)>>>> for 5.1 DD sound.

I want to ask:
When I connect my hard disk to the usb drive of TV, and play some music/movies, the sound is coming from the Tv and not from the AVR.

The USB drive of onkyo doesn't allow all video formats so I am no other option. The USB drive on my tv allow all video formats to be played, but I am not able to get the sound from my AVR.

Please help.