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    T420s: green light on fingerprint reader when machine off

    Discussion in 'Lenovo' started by rogerspass, Jun 6, 2011.

  1. rogerspass

    rogerspass Notebook Enthusiast

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    Hello everyone. I just got the T420s. Just a small question here. I found the green light on the fingerprint reader is always on when the machine is off. What's that function for? How can I turn it off. It seems consume some power. Thanks.
     
    rogerspass, Jun 6, 2011
    #1
  2. pkincy

    pkincy Notebook Evangelist

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    I agree. I don't see a way to have this turn off with this set of drivers.

    Perry
     
    pkincy, Jun 6, 2011
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  3. chaosphoenix

    chaosphoenix Notebook Consultant

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    Its so that you can power the machine on with the fingerprint reader. It draws an insignificant amount of power... nothing to be concerned about.
     
    chaosphoenix, Jun 6, 2011
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  4. hitman_36

    hitman_36 Notebook Consultant

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    You can switch it off from the Lenovo Fingerprint Software > Setting > More Setting
     
    hitman_36, Jun 6, 2011
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  5. mrpeaches

    mrpeaches Notebook Consultant

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    Your laptop battery could probably power that green LED for months before needing to recharge. I wouldn't worry about the power draw honestly.
     
    mrpeaches, Jun 6, 2011
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  6. Windsor

    Windsor Notebook Geek

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    I think it is more than that green LED got powered. The fingerprint reader must be kept powered at the same time so that it can keep detecting and validating any finger sweeping action for turning on the notebook. Overall power consumption probably is still very small but would be nice if that can be set to disable during Battery mode through Power Management.
     
    Windsor, Jun 6, 2011
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  7. JohnsonDelBrat

    JohnsonDelBrat Notebook Evangelist

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    As hitman said, you find the setting in the Control Panel > Hardware > Lenovo - Fingerprint Reader. After you get into there click Settings > More Settings and uncheck the box. This will shut off the light completely, even after the computer is turned on. However you will still be able to power up the computer with the reader (if that setting is also active).

    If you are traveling or something, I wouldn't allow it to power up the computer. It will continuously drain power. Although not huge amounts, it does add up.
     
    JohnsonDelBrat, Jun 7, 2011
    #7
  8. mrpeaches

    mrpeaches Notebook Consultant

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    Just as a follow up, I was browsing around and found this.

    So, it looks like you might be ok on the power drain front :)
     
    mrpeaches, Jun 10, 2011
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  9. John Ratsey

    John Ratsey Moderately inquisitive Super Moderator

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    I had wondered if Lenovo had wired this to the lid switch so that it when off when the computer is closed. However, the power drain of that little LED should be insignificant.

    John
     
    John Ratsey, Jun 11, 2011
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  10. Szab

    Szab Newbie

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    Fingerprint software -> Settings -> Authentication tab -> Power-on security section -> Use fingerprint scan instead of power on button

    Turn it off and then this feature will be completely disabled. No little green-light, no sensor-power when the machine is off.

    This solution does not disable the normal fingerprint-sensor operation nor it's green light feature when the computer is powered on.
     
    Szab, Jul 9, 2011
    #10