nRF52840 DK suddenly STOPED working.

[SKV]

Hello,

I stared working on nRF52840 for past few weeks, it was working fine. One fine day the board STOPED  working, when i was testing a experiment. I tried with different USB cables the board was not turning ON. When i connected the board to the external power supply i started working. When removed the external power supply it STOPED working again. It is working only with the external power supply not with the USB, what might be the problem?

Any Suggestion.

Thanks in advance. 

[SKV]

Hi,

The firmware flashed to the board was 802_15_4 (wireless_uart).

->I tried using nrfjprog -- recover it did not work.

->LED5 turns ON only when connected to the external power supply.

I reapplied the MCU firmware, it did not hlep.

Its OK i can manage with external power supply, but i have to carry the power when i am test different location.

[Simonr]

Have you cut any other solder bridges than the SB40? Could you check that the jumper on P22 is working properly?

Best regards,

Simon