I just bought a Samsung HT-C350 5.1 Channel surround system and have connected my TV to it via the optical audio output (as my LG 50PK550 does not have composite audio out) . My issue is that the sound is periodically cutting out for a second or two. Is it possible that this is due to the cable being loose? it didn't fit tightly in to the back of the unit. If it is the fault of the cable where can I buy a quality one?