Ok my Phillips my TV emits this high pitch squeal sound when the tv is off. When on it stops. This makes no sense to me. It's an Android TV. Is there something I can do in a standby setting where this won't happen or do I need to return it since it's within the return date?
I agree with the other comments here. Other things to check:
If it's coming from within the TV and not the sound bar or speaker it could be an indication of a bad/failing power supply. I think you should make a warranty claim if you can.
I have the same tv & the same issue. Just purchased the tv about a week or so ago. It’s a LOUD high pitched ring that stops immediately when I turn the tv back on.
This is usually called coil whine, and it has to do with the power supply components in the TV. It's usually on a higher power usage scenario rather than low, though.
Phone/tablet chargers will also often have this when plugged in but not charging anything.
It has nothing to do with it being Android TV.
On a side note, check if you hear the same noise in a different quiet room. It might also be tinnitus that the sound of the TV drowns out.
https://en.wikipedia.org/wiki/Electromagnetically_induced_acoustic_noise
TVs usually have some glue over some of the components to reduce this. So for your model if could be a one-off due to a manufacturing error or it could be a poorer design, which would mean it's likely on any replacement unit as well.