Originally Posted by Jason626
That date should already have the fan fix in place.
There's a lot of DIY stuff that some has said has helped to quiet the fans.
I can see the foam "fix" looking at the back of the unit. It does not appear to fix the problem, or at least not fully fix it.
Pushing gently on the back of the panel to the left of the fan on the left (when looking at the back), I can feel it deflect slightly.
That means the back is really a drum. If turbulent flow forms in the exhaust area and happens to sync up with the resonant frequency of the "drum", even tiny initial effects could turn into unacceptably large amounts of noise.
Removing the back would of course make the problem go away. The foam "fix" might, depending on placement of foam, reduce the resonance and thereby the noise, without actually attacking the root cause. (Noise reduction due to the foam "fix" would just be a side effect of the foam.)
Did anyone try adding mass damping to the back of the TV? I'm thinking some thick, heavy blocks of viscoelastic material might snub the oscillations and make the problem go away.
Similarly, chunks of viscoelastic material thick enough to contact both the inside wall and the inside of the back might prevent it from vibrating.