I have a Micro USB connector that is connected to 5V power supply directly: enter image description here

I removed all the other pins on purpose (for easier soldering) but when I plug it in it doesn't power up. I checked the voltage and it is ok.

Do I need to connect other pins for it to work? Do I need to also ground the outer shell?

  • When I've bodged a USB cable like that I'd normally short the three central pins (D-/D+/ID) together with a small blob of solder. No problems with those cables as yet, and there must be a dozen or so around my house.
    – goobering
    Oct 20, 2016 at 18:00
  • 3
    Just a thought but are you sure you have the polarity correct? Oct 20, 2016 at 18:27
  • I have a problem with space in my case. (I cannot fit normal micro-USB end of the cable). @SteveRobillard I am quite sure but didn't try. Can something break if i swap polarity?
    – Vojtech B
    Oct 20, 2016 at 18:42
  • You can test the polarity by testing the voltage of an unmodified cable and your modified cable - if the polarity is wrong you will need to swap the probes to get the voltage sign to match. No need to test by connecting to the Pi - and hence no chance of damage. Oct 20, 2016 at 18:44

1 Answer 1


The solution was to switch the GND and Vcc wires.

  • You may want to add a little more detail about how you determined that was the problem (how you tested it) and answer your question from the comment about damaging the Pi if you reverse the polarity. Oct 21, 2016 at 12:53

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