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I have an LED light strip connected to my computer via USB A. I want it to power off when the computer goes into sleep.

I’ve tried disabling wake-up events from all the keyboards and mice and other peripheral but the LED strip still does not shut off. I’ve also switched “Wake-Up Event By” setting in my BIOS from “BIOS” to “OS.” It still seems to keep the USB hub powered or at least keeps supplying the LED strip with power.

Can someone please tell me if I can just kill power to a USB hub on my motherboard or will it always draw power if it’s just a pure power needing device?

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  • Hi - even though you have turned off power on events where ever possible, the usb ports will always draw power when a PC is in sleep mode. The only way to cut off power to the USB decoration is to either unplug it or power off the computer. Also bear in mind that many new mainboards/pcs have power charging for some - if not all - of their USB ports which means they will be 'active' even though the pc is shutdown fully.
    – Jim Nielsen
    Commented Dec 4, 2016 at 23:24

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Easiest solution (if it works on your computer): Try plugging the USB device into different USB ports.

Some computers will supply power to some but not all ports in different modes. In some cases the ports with power supplied in more states will have a lightning bolt icon by them. That (as Jim Nielsen mentioned in a comment) could refer to power delivered in the shut-down state, but it sounds like you would want to avoid those ports in any case.

Next step: Try looking for settings to change in your BIOS.

That one is a shot in the dark, but there is definitely hope, since some computers cut power to the USB ports upon switching to sleep mode. I just double-checked and that is how it works with my computer.

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It can be done. Depends on PC or Laptop you have. On Windows OS .go to power options. Select Advanced opptions. Look for usb / pci selective sleep maximum energy saving. Setting . Only thing that know will wake it back up is press Excape. On laptop key board. As usb mouse will not work until it wakes.

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USB is designed to keep port power always ON. The power management is accomplished by USB devices that must switch into lower power mode in 10ms after seeing USB bus SUSPEND state. Therefore you should not expect VBUS to go off ever, except when the USB host (typically a laptop) does not trust USB devices and turns VBUS power off when go asleep. It is called "cold SUSPEND", as opposed to the normal USB "hot SUSPEND".

Therefore, the normal way for your LED strip to be off is if you have the lights behind a full-function USB device, and the device has a MOSFET to turn power to your LED off when it senses the USB SUSPEND state.

Alternatively you can have VBUS turned OFF only if

  1. You have a good hub that has dedicated port power control high-side switches, and
  2. You have an application that can issue ClearPortFeature(PORT_POWER) command to the port. And then turn the port on on system resume.

If you don't have any of the above (good hubs are rare and expensive, and software to control USB ports does not legally exists), you are out of luck.

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