1. Welcome to TechPowerUp Forums, Guest! Please check out our forum guidelines for info related to our community.

My USB's have power when the computer's turned off?!

Discussion in 'General Hardware' started by Black Panther, Oct 19, 2012.

  1. Black Panther

    Black Panther Senior Moderator™ Staff Member

    Joined:
    May 30, 2007
    Messages:
    8,561 (3.27/day)
    Thanks Received:
    1,916
    Yesterday I attached a small USB fibre-optic ornament to the pc (White Bengal in system specs). I turned the pc off but didn't switch everything off from the wall-socket. The ornament remained lit. At first I thought it was extra charge in the PSU but not after an hour and more?

    This morning, I noticed the ornament lit up as soon as I switch on power from the wall socket. Even though pc is not powered and not running. :wtf:

    I checked the same thing out on my previous pc (Black Panther in system specs) and the USB doesn't have current in it when the pc is off.

    Is there something wrong? :eek:
  2. btarunr

    btarunr Editor & Senior Moderator Staff Member

    Joined:
    Oct 9, 2007
    Messages:
    28,260 (11.35/day)
    Thanks Received:
    13,586
    Location:
    Hyderabad, India
    Your motherboard doesn't deep-sleep. Go to the BIOS setup program, and under the power-management settings, look for "ErP Compliance" mode or "Deep S5 mode", enable it.

    [​IMG]
    Black Panther says thanks.
  3. Black Panther

    Black Panther Senior Moderator™ Staff Member

    Joined:
    May 30, 2007
    Messages:
    8,561 (3.27/day)
    Thanks Received:
    1,916
    Never heard about that :eek: I thought I had messed up something when I built the pc..

    Now that I know that there isn't anything shorting out, I'll leave it as it is because I actually like having the decoration light up even while the pc is turned off.

    I still can't figure out how this works electronically...

    It means that the PSU is still receiving and sending current from wall-socket to the motherboard and USB's even though the PSU is in the 'off' position?
  4. Derek12

    Joined:
    Jan 12, 2010
    Messages:
    1,096 (0.66/day)
    Thanks Received:
    163
    PSUs have a +5V Standby rail which is always on even if computer is off, and most modern mobos use it for powering up USB devices :)
    Black Panther says thanks.
  5. Black Panther

    Black Panther Senior Moderator™ Staff Member

    Joined:
    May 30, 2007
    Messages:
    8,561 (3.27/day)
    Thanks Received:
    1,916
    Great info! Thanks everybody :respect:
  6. entropy13

    entropy13

    Joined:
    Mar 2, 2009
    Messages:
    4,901 (2.48/day)
    Thanks Received:
    1,188
    And your PSU has a 3A +5VSB rail, most likely more than enough for your decorative light.
  7. brandonwh64

    brandonwh64 Addicted to Bacon and StarCrunches!!!

    Joined:
    Sep 6, 2009
    Messages:
    18,479 (10.32/day)
    Thanks Received:
    6,014
    Location:
    Chatsworth, GA
    Its cool cause you can charge your phone or tablet while you sleep :)
    Crunching for Team TPU
  8. Wrigleyvillain

    Wrigleyvillain PTFO or GTFO

    Joined:
    Oct 13, 2007
    Messages:
    7,648 (3.08/day)
    Thanks Received:
    1,765
    Location:
    Chicago
    Yeah I have a strip of white LED lights power by USB under my monitor panel and it stays on unless I flip the switch on the PSU.
  9. de.das.dude

    de.das.dude Pro Indian Modder

    Joined:
    Jun 13, 2010
    Messages:
    7,521 (4.98/day)
    Thanks Received:
    1,951
    ^ this.

    this is actually present to support USB charging feature of many devices like tablets and phones and mp3 players and stuff.
  10. hat

    hat Maximum Overclocker

    Joined:
    Nov 20, 2006
    Messages:
    16,899 (6.01/day)
    Thanks Received:
    2,061
    Location:
    Ohio
    Yup, that's what it's for. Nothing's wrong, it's actually a feature.
    Crunching for Team TPU
  11. Krazy Owl

    Krazy Owl New Member

    Joined:
    Jan 12, 2012
    Messages:
    900 (0.96/day)
    Thanks Received:
    77
    Location:
    Montreal
    I have that on my backup rig Socket 754 AMD. It's a good feature but imho it's more prone to blow the system if there is a lighting strike. I'm not an expert so it's only a guess.
  12. Jstn7477

    Jstn7477

    Joined:
    Aug 30, 2009
    Messages:
    3,797 (2.11/day)
    Thanks Received:
    1,493
    Location:
    Sarasota, Florida, USA
    All ATX systems for the last 15 years require the 5VSB rail for other reasons (Wake on LAN, Wake on KB, etc.) and motherboard manufacturers began allowing USB ports to use that rail instead of only the onboard LAN adapter and PS/2 ports. We weren't really connecting our mobile devices to our PCs until the mid 2000s when feature phones and eventually smart phones with USB connections became prominent.
    Krazy Owl says thanks.
    Crunching for Team TPU More than 25k PPD
  13. de.das.dude

    de.das.dude Pro Indian Modder

    Joined:
    Jun 13, 2010
    Messages:
    7,521 (4.98/day)
    Thanks Received:
    1,951
    i think all PSUs have lightning protection now.
  14. Aquinus

    Aquinus Resident Wat-man

    Joined:
    Jan 28, 2012
    Messages:
    6,011 (6.56/day)
    Thanks Received:
    1,957
    Location:
    Concord, NH
    I built my parents a rig some time ago with a 2600k and a Gigabyte P67-UD4-B3 and IIRC the board has a jumper to switch certain USB groups between +5vsb and +5v with +5vsb being the default.
  15. Derek12

    Joined:
    Jan 12, 2010
    Messages:
    1,096 (0.66/day)
    Thanks Received:
    163
    In my case I use a power strip w/surge protection and switch, but I still unplug it when not in use for a long time i.e night, watching TV, etc.. I had bad experiences with thunderstorms and appliances...

    Also it can save some money on bills especially if electricity is expensive like here :)
  16. Aquinus

    Aquinus Resident Wat-man

    Joined:
    Jan 28, 2012
    Messages:
    6,011 (6.56/day)
    Thanks Received:
    1,957
    Location:
    Concord, NH
    I have pretty hefty surge protection on my UPS. Heck, if the power quality gets too low it switches to the battery. One of the best investments I've made.
  17. Derek12

    Joined:
    Jan 12, 2010
    Messages:
    1,096 (0.66/day)
    Thanks Received:
    163
    Yeah I want a UPS too but here they are too expensive :(
  18. Urnighta New Member

    Joined:
    Nov 1, 2012
    Messages:
    2 (0.00/day)
    Thanks Received:
    0
    There might be some issue in your mother board
    Last edited: Nov 2, 2012
  19. Aquinus

    Aquinus Resident Wat-man

    Joined:
    Jan 28, 2012
    Messages:
    6,011 (6.56/day)
    Thanks Received:
    1,957
    Location:
    Concord, NH
    Or maybe his motherboard is using +5vsb like the specs on Gigabyte's site says. :slap:
  20. Mussels

    Mussels Moderprator Staff Member

    Joined:
    Oct 6, 2004
    Messages:
    42,020 (11.71/day)
    Thanks Received:
    9,406
    i know i'm going to have issues with this in my next build, simply because i have a backlit keyboard.


    one of those weird 'features' that not everybody wants.
  21. Aquinus

    Aquinus Resident Wat-man

    Joined:
    Jan 28, 2012
    Messages:
    6,011 (6.56/day)
    Thanks Received:
    1,957
    Location:
    Concord, NH
    I thought that there is a jumper on the motherboard to switch it on and off for different USB ports. At least I think that was the deal with the P67A-UD4-B3.

    Edit: Hmmm, manual is lacking information. That is strange. I would imagine that you would be able to change it though. Forcing it on sounds incredibly stupid.

    Edit again: Wow, gigabyte says this in their manual.
    Last edited: Nov 1, 2012
  22. Mussels

    Mussels Moderprator Staff Member

    Joined:
    Oct 6, 2004
    Messages:
    42,020 (11.71/day)
    Thanks Received:
    9,406
    from the amount of threads on this subject lately, i'm going to say not all boards have it. mine has it only on specific ports, which is a good compromise.
  23. Derek12

    Joined:
    Jan 12, 2010
    Messages:
    1,096 (0.66/day)
    Thanks Received:
    163
    No, it's fine.
  24. de.das.dude

    de.das.dude Pro Indian Modder

    Joined:
    Jun 13, 2010
    Messages:
    7,521 (4.98/day)
    Thanks Received:
    1,951
    lightning has a better chance to get through the ethernet cable. ofcourse this is true for people with underground power cabling. I have had a vblown lan card once. lol. rest of the system was ok :)
    Derek12 says thanks.
  25. Wrigleyvillain

    Wrigleyvillain PTFO or GTFO

    Joined:
    Oct 13, 2007
    Messages:
    7,648 (3.08/day)
    Thanks Received:
    1,765
    Location:
    Chicago
    Yeah. And I only just recently learned this.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guest)

Share This Page