It seems as though my pi zero does not boot or send image through HDMI until I attach the USB hub. Why is this and can this be fixed?

  • How are you powering the Pi? Mar 19, 2017 at 2:44
  • @SteveRobillard I am powering it with a USB battery pack connected to the power in port. The hub that it will not turn on without is plugged into the other USB port.
    – ajflj
    Mar 19, 2017 at 2:52
  • I have a feeling it is only working when the hub is connected because it is back feeding power through the hub. With only the battery pack connected what is the voltage on the 5volt GPIO pin? Mar 19, 2017 at 2:57
  • @SteveRobillard 5v GPIO pin? Is that on the pi zero? How do I check it if so.
    – ajflj
    Mar 19, 2017 at 3:00
  • It is one of the GPIO pins and you test it very carefully with a multimeter. Mar 19, 2017 at 3:04

1 Answer 1


Yeah, this could be because they power supply you are using is not supplying enough power. Do you have your default power supply (Should've came with the Pi)? The Pi requires 5 volts for it to run, and so your battery pack may not supply enough voltage. You can check you battery pack for a little sticker or something saying the input voltage (going in) and output voltage (out to the Pi). On the original adapter i know it is 5 volts.

Also, what USB? An additional power source? A storage device? If it is power, it will probably only boot because it has enough power to rather than you just trying to boot it with your one battery.

I hope this helps, Dallin

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