4.1.2 Structure of laptop power circuitry
1)  Laptop power system is the third key component inferior to CPU, motherboard and display. Power system is composed of power adapter, charging battery and power management system etc.
2) Power adapter, generally, is composed of shell, power transformer and commute circuitry.
It’ll take some time to open power adapter shell. Laptop power adapter’s shell is fused quite close. It’s almost impossible to open it right off. After opening power adapter shell, it would be quite hard to return it back. By this point, we could identify whether the power adapter is original.
3) The effect of the metal shield layer on it is self-evident. It could keep out the damage to the circuitry from static. And check up the inside of power adapter, it includes capacitors, resistors, switch diode, power core chip etc, which all heat much.
4) So far most laptop power adapters are about 65 to 70W, the heat produced inside mainly spread out through the plastic shell. Of course the surface temperature of the power adapter is still quite high, and the inside of the adapter is almost a standard stove. Generally AC adapter’s maximum normal working temperature is about 70-80 degrees, therefore, when use a laptop, don’t pile up anything on it as possible as you could, especially some flammable material. Otherwise, unpredictable and unnecessary danger may happen.