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. 

[Simonr]

Hi

A few more questions from my side:

• What firmware was flashed onto the board when it stopped working? Are you able to recover it by using nrfjprog --recover in the command line (you'll need to download the nRF command-line tool first for this to work)?
• Is the debugger LED (LED5) still on when you power it through J2?

You can also try to re-apply the Interface MCU firmware to the debugger chip on your DK, as described in this case.

Best regards,

Simon

[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.