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I have two laptops (black and white) both connected to the same mains.

when I then with Ethernet cable and connect black laptop to AC adaptor, white laptops's touchpad starts glitching: can't move/press buttons, cursor is oscillating even when I don't move finger.

  • Disconnect black laptop from mains - glitch stops
  • Disconnect Ethernet cable - glitch stops
  • When black laptop is charging, it is more likely to occur then when it is idle and charged. White laptop's touchpad starts glitching not when I plug in AC adaptor, but when charging LED lights up.
  • None of AC adaptors are grounded.

How can one laptop influence the other through the Ethernet card? Is there easy way to prevent it (apart from temporarily disconnecting the cable, AC or using USB mouse)?

share|improve this question
"mains" what are these? – Simon Sheehan Mar 28 '12 at 21:43
Wall socket, where the AC adaptor is connected. – Vi. Mar 28 '12 at 22:00
@SimonSheehan - It's standard nomenclature in most of the English speaking world. Here in North America I find most people just say 'plugged into the wall' to mean the same thing. – Shinrai Mar 28 '12 at 22:09

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