Thought this info may help someone else:
We bought a "like new" 2014 International 25FB. The TV sound was bad and cut out. It was worse through the Sony system speakers. I discovered that if I unplugged the Sony system speakers (2 RCAs), the TV sound was fine. I called Airstream and they said Samsung modifies the TV for them by adding the RCA connections directly to the internal speakers (RCA cable just dangles out the back of TV). So, I disassembled the TV to check the soldering points. They all looked good. A replacement TV was about $500! (28" TVs are normally about $200).
Bought a cable - 1/8" mini plug to 2 RCA connectors, and a right angle adapter (for the tight space behind the TV). Connected this from the TV headphone jack to the RCAs that go to the Sony system.
Cost: $12 (Radio Shack)
The only downside is - to use TV internal speakers, I have to unplug the headphone jack (very easy with right angle adapter). However, I like the sound better through the Sony system, so I just turn it on also. It's easier to hear.
Not a perfect solution, but works great for us.