nrf52840DK not detected after flashing an external board

RE: nrf52840DK not detected after flashing an external board

Simonr — Wed, 04 Jun 2025 09:30:52 GMT

What voltage is the external board running on? If the VCC goes too high it might have burned the nRF52 DK I'm afraid.

Please make sure the external board is connected to the DK as per the image below.

Best regards,

Simon

RE: nrf52840DK not detected after flashing an external board

j_sudria — Fri, 30 May 2025 16:04:28 GMT

Hi Maria,
I checked and everything is connected as you indicated. I also tried measuring the voltage on the VDDnRF pins of the p20 connector and I get 0.4V. As far as I know I should measure a value close to 3V, right?

RE: nrf52840DK not detected after flashing an external board

Maria Gilje — Fri, 30 May 2025 08:55:18 GMT

Hi Jaume,

First, let's do a sanity check and make sure that the switches on the DK are in the correct positions and that you are using the correct USB connector.

SW6 should be on DEFAULT

SW9 (nRF power source) should be on VDD

The correct USB connector is J2.

If you verify the above steps we can investigate more about what is going wrong.

Best regards,

Maria