220 volts make Macbook Pro Vibrate
I'm using a USA Macbook Pro in China and noticed that when I plug in the power which is 220 volts the laptop vibrates. I do not feel this vibration while I use my laptop in the USA which uses 110 volts. I've also had problems with my USA hard drives vibrating and even Final Cut Pro being very unstable while using it in China. I was wondering whether this vibration is normal and whether it could possibly harm my laptop. Any info would be much appreciated!