Two units received, one DOA?

Got my 2 cores a few days ago. One works fine, the other one looks very much like DOA to me.

  • RGB led not flashing or lighting in any way
  • No reaction to any action on the MODE or RESET button or combination of both (for factory reset).
  • Reset led won’t light.
  • Device warms up a lot after 2-3 minutes (can’t touch it).
  • No WIFI connection of course.
    Same results with different cables, all cables work correctly with the other unit.
    And by the way the connector on the core side of one cable constantly pops out when disconnecting it from the circuit.

Any suggestions ?

You can’t call 50 % DOA on a 2-unit sample significant statistics, it’s just a bad user experience. I notice however that there are other cases where customers receive units that do not all behave the same way: I suggest that a serious look at your production process is required.

The most significant point is that “Device warms up a lot after 2-3 minutes (can’t touch it)”. Especially that part in parenthesis. My good part only slightly warms up. The bad part (probably unprogrammmed) stays cold.

Do you have a way to measure the current draw on the USB power line? I really suspect you have a short on the board or inside a chip. Probably the TI chip if it is that chip, which is on top, that is getting hot.

I suspect that you are going to need to return that part. Is it still in the breadboard? Can you check to make sure none of the pins has been bent and is touching a neighbor?

(Board level Electronics Engineer, but still coming up to speed on this unit)

Hi @JMarc,

If the chip is getting too hot to touch and doesn’t respond to a factory reset, then it sounds like it could have a short and we should do an exchange! Can you email us at and we can arrange a replacement?