I've come across it once with a laptop power supply. I believe it correlated to a voltage issue of some sort. We just replaced it with a new one and the problems disappeared. It definitely wasn't coil whine, but I didn't believe the person complaining about it until I held it up to my head myself.
I've come across it once with a laptop power supply. I believe it correlated to a voltage issue of some sort. We just replaced it with a new one and the problems disappeared. It definitely wasn't coil whine, but I didn't believe the person complaining about it until I held it up to my head myself.