| From: Russell Reiter via talk <talk@gtalug.org> | I power off, unplug | the power cable and press and hold the start button for a few seconds to | see if I can dissipate any lingering bus voltage. I don't have a "manual" | troubleshooting direction to do that, but things did start acting better | when I started to do it. This was a practice I used to do diligently in the | 90's, from before switched power supplies, but I never needed to do it much | after 2000. At first I thought you meant "switching power supplies", but they were introduced much earlier. Now I'm guessing you mean power supplies that are switched on and off by the motherboard, rather than by a direct power supply switch. I guess that came in with the PS/2. (A lot of PC power supplies also have direct switches but those switches tend not to get used.) If you turn off a PS through the motherboard, there is still some power available. I infer it is used for - turning on the computer via a firmware timer (I often see this option in a firmware setup page but have never used it) - USB charging even when the computer is off - wake-on-thing (LAN, Keyboard, mouse, whaterver) - lights-out updates If you turn off the direct power supply switch, none of that will work. Unplugging the power supply from the wall should have the same effect. Anyway, your procedure should really reset things in a way that might not happen otherwise.