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Here is what happens:

  1. I put my laptop to sleep.
  2. I turn on my light
  3. My laptop wakes up.

Why does this happen?

BTW, they are both connected to the same power strip. Could my laptop recognize changes in power from a 90 watt bulb? Is that what is causing it to wake up?

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2 Answers 2

up vote 4 down vote accepted

Maybe your problem is something like a "transitive frequencies" on your eletric net. When you turn on your light, the switching on process generates a lot of undesirable frequencies inside your eletric net. Your BIOS may be interpretating the strange signal on the source power as a turn-on signal. There are some option on your BIOS that allow your computer to turn of when specific events happends, such as a signal on your telephony modem and on your ethernet card. Take a look on your BIOS and disable these options(if it was enabled). If ths don't solve the problem, maybe your laptop's source power is having a more complex trhouble.

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Hummm.... I'll look into it (in approx 10 hrs.) (+1) –  wizlog Nov 23 '11 at 13:05
    
Another way to try to solve this problem is changing your light for another one that creates less "undesirable harmonic frequencies" than an incandescent lamp. You could try to use another one, such as an eletronic lamp(en.wikipedia.org/wiki/Compact_fluorescent_lamp). By the way, is your actual lamp an incandescent one right? –  Diogo Nov 23 '11 at 13:10
    
Yes, I am using an incandescent light bulb. Why are you so sure that I'm having a problem with transitive frequencies or any kind of frequency? If I plug the light into another outlet, one not connected to the power strip, nothing happens to the laptop. –  wizlog Nov 23 '11 at 13:12
2  
These kind of lamp bulbs, when energized by the fisrt time (on swtching on process) creates harmonic frequencies on the power strip related to the fact of abruptilly switching. You can find more information on google about it. Eletronic bulbs(the good ones) have a supressment circuit to reduce this effects on your eletronic net. The fact that your computer is returning from sleep I think that is related to the BIOS option that allow you to get your laptop turned-on from specific external events, as I said, such as ethernet device pulse. –  Diogo Nov 23 '11 at 13:20
1  
Maybe the problem is your eletric power strip then... I can't see another explanation unless problems related to the harmonic frequencies. –  Diogo Nov 23 '11 at 13:24

This may also be a different unrelated bios setting to the 'ethernet wake' setting. The power strip limits the surge current drawn from the wall inherently. When you turn on the light, the current draw goes up dramatically, but the total wattage is limited by the strip.

To keep the current draw high, the voltage sags. What may be happening is the laptop may be recognizing the sag as a power unplug/plugin event sequence. I am guessing that your computer is set to wake on power.

Simply turning that option off in the bios I am presuming would stop this from happening. You can test this by putting your laptop to sleep, unplugging it from the wall, and then plugging it back in, to see if that wakes it up.

I have seen wake on lan triggered by stray emf before, but that is a rare case, and not something that would happen every time. The wake on power setting I have seen triggered repeatedly in the past by just such circumstances.

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I'll try it, thanks (+1) –  wizlog Nov 23 '11 at 17:36

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