Hooking up surround sound. i just bought a samsung surround sound system and cant seem to get it

Question

i just bought a samsung surround sound system and cant seem to get it working correctly i tried hooking it up to my sony 400 disc dvd player and i only get sound out of the subwoofer and two front speakers sound wont come out of the two rear spaekers or the center speakers coulf you please help me i also checked to see if it work when hooked up to my ps3 and they all worked