nRF52840 Not Detected by nrfjprog / Recover Fails - Need Expert Advice

[veelox321]

• • Hello,

    I'm having a serious issue with my nRF52840 board.
    Here’s what I already tried:

    ---

     What I have done:

    • Verified working USB cables (data + power).

    • Installed SEGGER J-Link drivers.

    • Installed nRF Command Line Tools (latest).

    • nrfjprog --help works fine.

    • Installed Zephyr SDK and built a simple hello_world project.

    • Tried west flash and nrfjprog --recover. 

    • Installed J-Link Configurator (no device shows up).

    • Tried multiple USB ports and cables.

    • Tried flashing with Arduino IDE — still no COM port.

    • Windows sees the device only as "USB Device" (driver missing). now it wont see it at all

    ---

     Current problem:

    • nrfjprog --recover gives:
      ERROR: No debuggers were discovered.

    • No COM port appears.

    • No J-Link detected.

    • Board only makes a USB connection sound when plugging in (sometimes). now not at all

    ---

    ---

    Thanks for your help! 
    I would like to try everything possible before giving up.

[Edvin]

Hello,

I'm having a serious issue with my nRF52840 board

Is that an nRF52840 DK, or is it a custom board?

If it is an nRF52840 DK:

1: You are using the USB connector on the short side of the DK, right?

2: If you already are, and the device is powered, can you please take a closeup of the DK, so that I can check the various switches on the DK, and see if they are all in the right state?

3: Have you tried another USB cable, to make sure that the cable is not broken, or that you are accidentally using a charging cable, which doesn't have data lines (only power)?

If you are using a custom board:

1: How do you connect it to your computer? Do you have an external debugger? How do you connect it?

Best regards,

Edvin

[veelox321]

Hi, i am unsure about the model, since im not the one who bought it but i think it is an adafruit feather nrf52840 express (https://www.digikey.ca/en/products/detail/adafruit-industries-llc/4062/9843410)
1 - i use the only usb available 

2 - There is no switches

3 - i have tried others usb cable, im confident they are data cable since it is working on other mcu

4 - i use an swd programmer i had the max32625pico which seems to work

thanks