Device not turning on, however BLE works, LED5 flashes once

[avijay]

So I am using the NRF5340, and it has been fine for a few months now, however today, it stopped working and sending any data between the USB and laptop, the LED5 flashes once and not again. Using a multimeter, I found that there is power in the device, but it isnt recognized thorugh JLink or VS Code. However, I had flashed a BLE application onto the device before this issue, with an analog input, and when I tried it out, it worked. Please let me know what can be done!

[Priyanka]

Hi Aditya,

Did you make any hardware changes on the board?

Is your board being detected by the PC? 

I had flashed a BLE application onto the device before this issue

Was this any one of the nordic samples?

Regards,

Priyanka

[avijay]

Hi Priyanka, thanks for your response! I did not modify the hardware of the board, and my PC is not detecting the device. I had flashed the Nordic samples before, but this was a version of my own code that used a small potentiometer. The device still works with the potentio and the BLE connection with the connect app, but does not turn on LED5 or be recognized by my PC. Kindly let me know of next steps!

[Glenyz]

Hi, 

Please see if this thread helps: nRF5240-DK board not working

And for the MCU firmware follow this link: www.nordicsemi.com/.../nRF5340-DK

[avijay]

Thank you! Do you know how I may be able to enter bootloader mode for the nrf5340?

[Glenyz]

Assuming you are using the nrf5340dk, you need to hold down the RESET button while the device is off then turn it on while holding the button down. You should see LED5 slowly blinking on your board. After that follow the steps in the thread that I linked above.

Hope this helps.

[Priyanka]

Hi @Aditya Vijay   Glenyz 

This could be done only on previous DK versions where the Debug chip was a SEGGER chip. In the 5340DK and later versions of all other DKs, the Debug chip is the 5340SoC and it's not possible to re-flash the fw onto it. 

So if the issue is with your Debug chip (which could be the case), then please try using an external debugger, or you can use the DebugIN (P18) from another DK to flash onto this one.

-Priyanka

[avijay]

Hi Priyanka, I tried to use a J-Link Segger and unfortunately it could not read nor detect the nRF5340. I tried sending commands but it would not pick it up either. Are there any other steps beyond that?