Generally speaking, the role of the power adapter ground is a transformer and rectifier. Household AC is 220v, and our computer land is DC 12v (as if), so, can be sure that the power adapter is a transformer cum rectifier.
Adapter is a transformer, then we should know, AC 220v through the transformer voltage, through the rectifier into DC, here is the consumption, and these consumption will be transformed into heat,
so the power adapter will be hot is also normal. Transformer is made of silicon steel sheet, transformer energized, resulting in magnetic flux, magnetic flux will incur between the silicon steel sheet to generate the role of force,
thus generating buzzing sound, which is normal. But too hot earth sound is not normal, due to many reasons: 1, AC voltage instability. 2, chip damage. 3, turn-to-turn short circuit. 4, component damage, etc.. By the way,
the role of the adapter is to convert alternating current into direct current electronic products!
Power adapter space is generally built-in, general adapter volume are not small, small volume of the machine are external, in order to save space, two to replace also convenient,
adapter with the mains, the voltage is relatively high, put the machine inside more dangerous.
