I've tried to connect the external WD My Passport directly to Raspberry Pi 2.0, but experienced some issues.

When max_usb_current=0 HDD is running (but with some strange ticks) but is not detected. In case when I set max_usb_current=1 HDD is working OK. But I see some strange artifacts on display. Small ~20px*20px square filled with RGB radial gradient (same as during NOOBS boot) appears in upper right corner. I've noticed that it appears only when HDD read operation occurs and is on top of anything. Does anybody know how to fix it?

I'm using 12W (2.4A) Apple iPad power supply. It happens on any Raspberry Pi distros (OSMC and Raspbian). Only Logitech wireless keyboard adapter is connected to USB port beside HDD.

P.S. When I'm using Y cable and connected HDD to extra power source issue disappears no matter whether max_usb_current set to 1 or 0.

2 Answers 2


The image you are describing is the Pi's way of telling you that it is not getting the required voltage. You should be powering the HDD from an external powered hub, not from the Pi directly. More info can be found in this thread.


The rainbow square tells you that the Pi's voltage is low.

The Pi2 can power an HDD from USB with the max_usb_current setting, and 2.4A should be enough, depending on any other devices which may be connected, but a bad USB cable from the power supply can affect the voltage.

My advice is to diconnect any other devices and try other cables. If that doesn't help, the power supply may not be good enough, regardless of what's printed on the case.

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