My hard drive is a 3.0 1TB seagate with Wi-Fi (NTFS). It needs 5V and 2A.
My device is Raspberry Pi 2 B running Raspbian.

I created a Y-Split USB 3.0 cable. One end is going to the Drive (obviously) There is one end going to a wall charger (the one that came with the hard drive) ---> ONLY THE GROUND AND POSITIVE WIRES ARE ATTACHED.

The other end goes to the RPi where the Ground and Positive wires are completely disconnected since I am getting power from somewhere else.(But the data wires are all still connected.

I tested it on my Windows desktop and my Windows laptop and the drive works perfectly fine.

I have nstf-3g installed on the pi. The drive has always been used with windows machines previously. When I type sudo blkid, the drive does not show up.

I tried googling for this issue for a while now.. Every forum says it is because the Hard drive is not getting enough power and to connect the drive to a USB hub. But my drive is getting full power from the wall outlet.

I'm starting to wonder if the problem could be: since the positive and ground wires were completely disconnected from the USB cable's end going to the Pi, the Pi somehow does not know there is a drive connected there? I find it weird that it works on my windows machines then?...

If you need anymore information let me know.

1 Answer 1


I cannot guarantee that it will work if you split but you definitely need the ground also connected to the Pi

  • That seems crazy as it does work on my windows. Anyway. I will go buy a usb hub and try it with one. If it doesnt work ill just return it. Oct 23, 2015 at 16:30
  • powered usb hub works. thank for the help. I am really surprised the drive works on windows without a positive and ground connection but does not work on the pi. Oct 23, 2015 at 23:38
  • @DavidGoulet The Windows machine probably has an internal connection to physical ground and the USB cable also has a shield which is connected to ground, but it is not a recommended way to work.
    – Milliways
    Oct 23, 2015 at 23:43
  • oh ok. well.... me trying to save 40$ on a usb hub just ended up costing me 2 usb cables and a lot of time now did it not :P. still worth the knowledge and experience gain tho Oct 23, 2015 at 23:53

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