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Originally Posted by dupondje
http://www.dupie.be/dell/tests.html Check this. I just did some tests on my portable. If u connect a USB device to it, it uses that as ground ! Hope your usb devices will not break down ! 
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That's consistent with what I have experienced. I've gotten quite a few static jolts when plugging my USB hub into the the 9400. Keeping things is perspective, a static hit can be 1000's of volts, but very low amps. My 9400 is providing 0.25 amps. That's 250 to 300 milliamps, which is significant. Anyone else measuring amps? I've discussed this problem at length with two friends who are knowledgable in electronics. They agree that the stray current is not so much a problem, as the potential for static discharge backtracking. In other works, electricity, like water, chooses the path of least resistance. What this means is that, with some kind of connection established between the circuitry and the case, when combined with no ground, this would drive any static hit through the circuitry rather than to ground, with the potential of causing damage. Maybe this is the real potential problem with these units. For those who say this is normal, I disagree. My subsequent test of the Inspiron 8200 showed 0.5 volts. I've had other laptops such as the Compaq x6050US that did not seem to have these kinds of problems.