如果我0係日本買部 Denon DVD 機 - Model#1920 返香港, 我仲要做0的咩先可以0係香港用得呢?

You must have an transformer to transform the electricity from 220v to 120v as the voltage of Hong Kong is 220v while in Japan it is 120v. Make sure you have a right transformer before you plug in the power cord.