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

Can you check what position you have put the nRF power source switch (SW9) is in? It should be in VDD (middle position) in order to run normally.

Best regards,

Simon

[SKV]

Hi

Thanks for replying. The nRF power source switch is in the VDD position only. Any other method to solve the issue.

Thanks in advance.

[Simonr]

Have you cut any of the solder bridges on your DK? Please upload a hi-resolution picture of your DK so I can take a look. Can you tell me more about what experiment you were testing when the board stopped working?

Best regards,

Simon

[SKV]

Yes i have cut the S40 solder bridge for measuring the power and i have put a jumper to it. I was conducting an experiment on TiSCh for 802.15.4. This board was used as a receiver.

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