Does the property company have the right to ask the owner to remove the led billboard on his balcony?

The authority of property lies in the management right of public space. Note, it's just management. If other owners do not explicitly object or have similar agreements, the property has no right to interfere with the activities of community owners in public space.

In the owner's private space, the property has no right to interfere, and the right to interfere is called the neighborhood Committee! ! ! ! !

For example, singing karaoke at night will affect neighbors, especially neighborhood committees! ! ! !

In this case, unless the property can come up with a clear and effective agreement or prove that your behavior violates the property management regulations (the national regulations of the company are useless), you can refuse appropriately;

If the property refuses;

Neighborhood Committee! ! ! ! ! ! ! ! ! ! !

Neighborhood committees are actually members of their own families, but for various reasons, neighborhood committees and property are also in cahoots.