I have the ASRock Z68 Extreme4 Gen3 mainboard and my problem is that sometimes some USB ports are still on after I shutdown my PC...not only at the backpanel (like my mouse) but also the USB 3.0 connectors on the foreside.
I think this is actually a feature of your motherboard, as it allows you to recharge devices even when the system is off. The way around this is to get in the habit of physically unplugging the devices that you want powered off.
Thanks for the tips, guys. I will take a look in my BIOS...
If you don't have a power supply adapter for your MP3 player, this "feature" may be useful...
I don't want that all my USB devices are always on...and it is not reasonable to unplug the devices on each shutdown...
That FAQ gave three different methods to try, at least. If your board does have the jumper pad mentioned in the answer, that would be the most certain way to turn it off though turning it off by one of the two BIOS methods would make it easier to enable if you needed it later.
have usb mouse\keyboard that always power off on shutdown. also a USB 3.0 external drive which only powers off some of the time on shutdown. be sure it is not sleep/hibernate.
these times that the drive doesnt power down automatically: when i boot the machine the partitions on this external drive will not be detected correctly. the partitions will show and the first tier of folders but no shown files are accessible and the folders are empty. does not happen in Windows 8, only Windows 7. have tried a couple installations and same problem.
drive is perfectly fine and runs wonderfully in Win8. something funky with Win7 USB3.0 control. have updated Windows and Board drivers.
I got to this forum searching for "ASRock USB always on" I don't have the same motherboard but I had the same issue so...
The solution that worked for me:
There is a pin "PS2_USB_PWR1" and the options are 5V and 5VSB. I switched to 5V and the issue was fixed
I searched what 5VSB mean and in few words it allows mouse/keyboard or other devices to turn the computer on, for that it is oviows that the device should have power
The BIOS has an option to disable USB power on/off but it looks like turning those options off is not enough