Ok I've searched hours and hours and contacted Onkyo support. He said if my TV do not support ARS then I will need another connection to get the sound come out. So, I did bought optical cable for audio and connected from TV to Home Theater. I left my HDMI cable settings/connections. And boala! I have great sound in my Home Theater. I don't know if any of the Samsung supporting team even saw my posting, but I wanted to answer my own question if anyone have same questions and have difficulty setting up Home Theater System.
I am trying to hook up Samsung LN40C630 with Onkyo HT-S3400 via HDMI. What I did is following...
I hooked up one HDMI cable from HDMI out from home theater to TV HDMI in. Changed TV sound setting in menu to External Speaker. However, when I play a file from my external hard drive, there is no sound from the home theater. I also tried with TV sound setting with TV speaker, but the sound only come out of the TV speaker. So, I tried PS3, which is connected with HDMI to Home Theater HDMI IN. When I played blu ray movie, I have sounds and it is surround sound. So I don't know what the deal is with playing a file from TV. Any help would be appreciated.