There is a reason devices have a third prong: Dell’s new laptops don’t have a third prong (an earth ground). As the article mentions, users are reporting feeling slight shocks when touching the brushed aluminum casing…which is possible due to the absence of the third prong, which normally grounds the outer casing appliances (those with metal cases) or exposed metal pieces on an appliance. Without the earth ground, the AC power is converted to DC just fine, but the DC voltage is “floating” with respect to earth ground. For example, the AC mains could be converting to, say, 20Vdc, but this is simply 20Vdc between the plus and minus output of the power supply, and the minus side of the supply can be any voltage and is not necessarily the same as the earth ground potential. Normally one of two things happens: 1.) the minus side of the DC supply is connected to earth ground, or 2.) if no electrical connections are made to the outer casing, the outer case is connected to earth ground. This is done to ensure that anything the user touches will be at the same potential as the user, and no shock would result. If the case was not brushed aluminum, and instead plastic, the user would notice no difference, except when plugging in peripherals.
What I wonder is what the grounding of the case looks like. If the case has no electrical connections at all, and the case is developing a static charge that is discharging (which can develop thousands of volts – dragging your feet on the carpet and touching a door handle can easily build up tends of thousands of volts), there is no danger from these shocks, other than an annoyance. If, instead, the case is actually used as the ground reference for the computer, then this can potentially cause harmful shocks since power can be drawn out of the computer supply when the potential difference between the case and the earth ground is shunted through a user.
