How to flash BBB

Hi, guys.
We use BBB in our company as a part of remote watemeter data gathering and time to time I have to reflash BBB, because it does not answer.
I have 3 pcs of BBB and I cannot reflash any ot them.
What I did:
I downloaded “bone-debian-10.3-iot-armhf-2020-04-06-4gb.img” and moved it by Win32Imager to SD.
I inserted SD into BBB, hold S2 and switch power on.
It booted, i saw ping from
I was able to log in BBB by Putty and open “nano” editor by “sudo nano /boot/uEnv.txt” command.
I uncomented #cmdline=init=… and saved it.
I rebooted BBB by “sudo reboot” command.
BBB rebooted, but after 30 seconds all of LEDs light on and that is all.

When I tried to reboot it and hold S2 button, it has tha same results.

What to do and how to reflash BBB.

Many thanks for your answers.

Petr Filipi
The Czech Republic

That’s a flash failure…

Do you have a USB serial adapter plugged into J1 so we can debug?

Is there a model sticker on your board? A, B, or C?


Hello, Robert.
Thanks for your answer.
There are two sticks on BBB
The first:

  • near S2 switch, on the 46 pins black connector, there is written:
  • QR code (around 17x17 points)

The second:

  • on the ethernet connector, there is written:
  • QR code (cca 22x22 points)

BBB was bought by (i suppouse) RS components and it is, I hope, original.
I have no any debug cable - but i will buy it ASAP.
What I have is printscreen from my monitor - see enclosure.


Hello, Robert.
Now I have FTDI TTL-232R-3V3 cable (USB to TTL Serial Cable (3.3V)).
How can we debug?

Petr Filipi

please plug it in, share the full boot log for us to look at.