First thing I would suggest would be to confirm the polarity of the outlets. I have tried Snappers with balanced AC and they didn't like it, which suggests an unusual grounding issue. However, they were quiet with "normal" AC.
Second, disconnect the cable from the TV and turn off any dimmers and lamps with lo/hi switches. Also, seperate all the IC's and PC's.
Second, disconnect the cable from the TV and turn off any dimmers and lamps with lo/hi switches. Also, seperate all the IC's and PC's.