Comment by 15155
17 hours ago
There's zero chance that the DC ground in the laptop is tied to earth ground in the charger: they use LLC resonant converters and flyback converters (depending on vintage) - an earth ground tie would defeat the purpose of these isolated topologies.
No they isolate L and N not PE.
However it’s wired up the fact is the electric buzzing feeling goes away if you use a grounded extension cable instead of two pin.