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After I pressed Start >> Shut Down >> U, the computer goes off. But hass the power supply still got energy?

When I use my old power supply, after I shut down the computer, the light of my mouse is still on, indicating the motherboard still has energy connected to the mouse.

However, after I switched to a new power supply, and after I shut down the computer, the light on the mouse is off. So is this event controlled by the power supply?

What I concern is whether there is still wasting energy after I shut down the pc.

Secondly, if it is on, how much energy it is eating? Full power of the power supply?

And more importantly, I would like to state why I don't want to unplug my computer.

Here is the case:

I got a wall and a socket hole, and the socket is connected to a 6-sockets power strip. The power strip is plugged with many thing, most are computer accessories. One day I want to shut down the computer completely, so I turn off the switch on the socket which connected to my pc. It is fine for the day. And after a few times of this action, one time, after I switched off the socket, my house's electricity is all gone and I found out that there must be leaked electricity so that Leakage circuit breaker shut down the electricity supply of my house. I need to call the administrator of the building to release the electricity from outside of my house. And this event deformed the socket on the power strip which connected to the pc, no matter whether I turned on/off the switch, there is power in it, so I think its circuit was melt so that the switch cannot control it anymore.

After this, I checked many suspects for this event, the socket on the wall, it is replaced with a new one. The Leakage circuit breaker is fine(checked by professional guy). The power strip is replaced with a new one. Then I turn on my pc with the switch.(I don't remembered whether that is a turn-on or a turn off) Hell, all of the electricity was gone again, and the new power strip was deformed just like the previous one.

Then I replaced my old power supply, the brand of it is GTR, which infamous among computer users who says the power supply from brand GTR will make fireworks and is very dangerous.

Then I got a new supply, and now I've never try to turn off the computer by turning off the switch on the power strip. Too dangerous.

Now I remembered I've never turned off the switch on the back of the power supply before turning off the switch on the power strip. Do I needed to turn it off before? I need to be educated about this whole proper procedure to shut down a pc completely.

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This question is getting quite long. English is not my native language, if someone thinks my question is confusing, please tell me to clarify the point which is not clear. Thanks. –  lamwaiman1988 May 18 '11 at 17:33

4 Answers 4

up vote 3 down vote accepted

Yes, the power supply is still energized. The ATX Standby rail is still powered so that you can do things such as turn the computer back on (since it's firmware/software controlled).

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How much does that ATX stand by function require for a period of time? For example, one hour? And my power supply is 470W. –  lamwaiman1988 May 18 '11 at 17:32
    
The standby line usually supplies 5V at a minimum of 700mA or so (though many supply more). –  Ignacio Vazquez-Abrams May 18 '11 at 17:38
    
so according to the formula P=IV, the power rate of the standby mode is more or less 5W? –  lamwaiman1988 May 19 '11 at 1:19
    
After accounting for losses, sure. Although there is no obligation for the mobo to actually consume that much. –  Ignacio Vazquez-Abrams May 19 '11 at 2:04

From your question, it sounds as if your building is not wired safely. I suspect the problem has nothing to do with your computer. Instead, it is the building itself. The damage was not related to your computer at all. The timing was a coincidence, if I am guessing correctly.

In the United States, most electric power companies will let you borrow a special meter which you can use to measure the power consumption of an appliance, turned on and turned off. One common brand is "Kill-A-Watt". If one of these is available where you live, you can find out how much power your computer uses when "off".

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Modern computers do consume some energy while plugged in, the amount can very from model to model but roughly you can expect it to use about the same as a small nightlight or even less. As far as unplugging, if you properly shutdown your system and have a surge protector there is no reason you can't flip the surge protector's switch off after the shutdown procedure is complete.

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Everything plugged into the wall can draw power no matter how little it is. If wasting energy is your biggest concern, then unplug your pc from the wall after you shut it down.

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My old power supply got something wrong, when I unplugged it, it leaked electricity and burned one of my socket. Now I am fear to unplug it. –  lamwaiman1988 May 18 '11 at 17:07
    
Whoa. That sounds extremely unsafe. New power supplies should NOT do that. –  francisswest May 18 '11 at 17:09
    
I tried to shutdown the pc completely a few days ago, with the new PSU, and there is no problem to turn it on and off now. So I think it is just the old PSU leaking current. –  lamwaiman1988 May 31 '11 at 1:30

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