MagSafe 3 firmware update improved MacBook Air M4 aluminum case tingling

A lack of protective electrical grounding could explain the tingling sensation on the aluminium chassis of a MacBook Air M4, independently of the MagSafe 3 cable firmware.

When a MacBook is charging, a very slight tingling or buzzing sensation on its metal enclosure can sometimes result from capacitive coupling between the charger's circuitry and the computer's chassis.

This can occur with a two-pin power adapter that does not provide a protective earth connection.

A properly grounded power arrangement may reduce or eliminate the sensation, depending on the cause.

The MagSafe 3 firmware update might coincide with the improvement you noticed, but without technical documentation or controlled testing, there is no basis to conclude that it changed the electrical behaviour responsible for the sensation.

Changes in the outlet, adapter, cable connections, or other environmental factors could also affect the observation.

Because the sensation occurred repeatedly and has not disappeared completely, it is sensible to have the charger and electrical setup checked rather than assume the issue is resolved.

If the sensation feels like an actual shock, becomes stronger, or is accompanied by other signs of an electrical fault, stop using the setup until it has been inspected.

The key distinction is that the aluminium chassis is where you feel the sensation, not necessarily where the underlying fault originates.

Lack of protective grounding is one possible explanation, but the sensation alone cannot establish the cause.

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