Power supply for Beaglebone


I have got a problem to power up the Beaglebone.

I soldered the 12V into the Cape an nothing happens when it is connected to the Beaglebone. It is the second cape I tried with.

When I power up the Beaglebone directly the LEDs on it and the Cape are flashing as I expect. I also had success to control the camera.

Have you got any idea why the power supply is not working over the cape? Is it possible that the beaglebone is the problem? How can I make sure that the power for the beaglebone gets there? Where can I do measuring on the cape os board?

- Reimar


There is a fuse on the cape just behind the power connector, measure the resistance off the fuse to make sure it is not open or just measure for 12v to make sure there is voltage on both sides of the F1 fuse.



The fuse is ok. Can I check the output from the cape? Which pins make the power supply for the beaglebone? Is there a fuse on the beaglebone I could check?


There are test points on the Cape for +5v & 3,3V

check these as well if not already done.

the connector P2 on the cape which is a 46 pin connector

Pins 1 Ground.

Pin 3 is 3.3v

Pin 5&6 +5V to power Beagle Bone

Pin 7&8 +5V From BB PMIC

these are all indicated on the pdf doc link mentioned above.


I despair: I measure 12 V to 3.3 V power supply for the network adapter, but no voltage on said pins.

I can't imagine that I have got two broken capes...

If I power up the BB over the 5V-input I have 5 V at 7/8


How are you powering the boards?

If the power is connected to the Cape then you would see 12V at the fuse on the Cape. If you are powering the cape from the Beagle Bone then you will not see 12V on that fuse.

If you have 12V power to the Cape you should see +5V on the test points on the cape as well as 3.3V. you should see this even with the Beagle Bone disconnected from the cape which may be a good test to make sure the BB is not pulling these voltages low. let me know what you see.


Hi David,

sometimes if you use a power source you should make sure to use correct polarity... I feel really stupid. Thank you for your help. :)



It happens :)

Great to see you move forward on your project now let's see some pictures under water :)