New, generic AC adapter is causing my computer speaker system to hum. I thought it was a ground loop, but a cheater plug (fitted on the jack of the AC adapter) didn't help. (The speaker system itself is not grounded.) I know it's the AC adapter, because if I run my laptop on battery power, the hum disappears. Anything I can do, short of forking out $70 for an original adapter? This adapter has been working fine otherwise. [more inside]
posted by ori on Mar 23, 2009 - 8 answers

My phone has a loud buzzing noise. When I touch the screw on a lightswitch plate, sink faucet or a metal lamp, the buzzing stops. What is happening – and more importantly how can I use the phone without having to ground myself? [more inside]
posted by kamelhoecker on Apr 12, 2007 - 4 answers