external USB always on

I have a little 40 GB Western Digital Passport external hard drive. It has not malfucntioned and is a great because it does not require its own power source, rather it runs off of the power that the USB jack provides. I noticed that when I plug it in to one of my PCs, it remains on regardless of whether the machine has been shut down. The PC in Quesion is a Falcon Northwest Talon with a 1.5GHz AMD Athlon, 512GB RAM, nVidia nForce 415D chipset, MSI K74N415 Pro motherboard, and a 500W power supply. I thought it might be the power supply, but I'm not sure. Any insight is appreciated, thanks.

 

The motherboard is still getting power, regardless of if you have shut down or not. USB devices are still powered by the motherboard, even if the computer is shut down, yet plugged in. The best way to make it stop, assuming you want it to, is to just unplug the USB from the computer and/or external hard drive.

Scout353

 

Thanks for your reply. I've also noticed that this does not happen on other machines. Perhaps it is the wattage of the power supply...