Turn off power to USB port during sleep/soft off?

[bjcsoln]

Does anyone know if it is possible to turn the power off on a (specific if possible) USB Port (preferably one that is on the MOBO rear panel vs one of the front panel ones).

I know by default these ports are left powered so you can use kybd/mouse to turn computer back on, but because I am using the USB port to power my LCD panel, when I turn the computer off or set it to sleep, the panel stays on, and without an active display, it just shows a bright blue screen.

I guess another option would be to jury rig a USB cable into the 4 pin molex and tap the 5v off from there.

 

[Marzipan]

what's your use case? I'm curious...

 

[Entz]

Is there any firmware for the screen? Sometimes there is a sleep timer you can setup.

Sometimes the board designers allow ports to fully shut off. Not sure if you have tried other ports. This may be more common on laptops though.

Your idea of pulling 5v would work fine if it isn't used for data. Short of killing the 5v standby power rail to the whole system and/or hacking together something with a relay/transistor I can' think of anything else. Maybe the internal headers don't have standby and you can use a PCI-e adapter.

 

[Marzipan]

I don't know how I missed the mention of LCD panel.

that said, Windows should hopefully allow you to create a power profile for the display

I'd also look at the manual to see if it has any details on having it go to sleep after a certain amount of idle time.

 

[Shadowmeph]

I think it depends on the motherboard some USB ports can be turned off and on but I think that the setting at least on my older Motherboard asrlock z77 the setting is in the Bios my newer on I left alone so that my keyboard can wake my PC from sleeping

 

[bjcsoln]

MOBO I am using is the ASUS Hero VIII, case is Thermaltake P3. LCD does not have any drivers or documentation that I can find.

Mr Friendly - I don't think it would be possible to create a power profile for this display, unless that profile could access a specific USB port.

Entz - yes - I am 98% sure the USB port is only used for power. There is a second USB port that is for touchscreen (so it would use data) - so I think I can try pulling off one of the molex connectors. Basically the same as what happens for my pump - it shuts off when the computer is off (or in standby).

 

[bjcsoln]

what's your use case? I'm curious...

Sorry - specifically the use case is - a USB port is powering an external LCD screen (that displays system temps and such). When I put the computer to sleep, or even soft power down, the USB port still provides power, so this screen stay lit up. I would like it to turn off along with the computer.

 

[lowfat]

Sorry - specifically the use case is - a USB port is powering an external LCD screen (that displays system temps and such). When I put the computer to sleep, or even soft power down, the USB port still provides power, so this screen stay lit up. I would like it to turn off along with the computer.

If the USB device is only getting power from the USB port then its up to the bios. But if you are using any powered USB hub, it could also be powering usb devices plugged in to the motherboard.

If it is a USB device that also communicates via usb, then you can check the device in device manager. Some devices will have a power management tab, where you can check to 'turn off device to save power'.

 

[bjcsoln]

If the USB device is only getting power from the USB port then its up to the bios. But if you are using any powered USB hub, it could also be powering usb devices plugged in to the motherboard.

If it is a USB device that also communicates via usb, then you can check the device in device manager. Some devices will have a power management tab, where you can check to 'turn off device to save power'.

Lowfat, I see where you are going here. I took a quick poke at this and while I think this could work, I will try the USB to molex for the 5v first/ I think its the easier option and then if that doesn't work,. I can poke around to try and find the speciifc USB port power settings.