Pretty new to development, compiled and flashed Zephyr basic samples through nrf Connect for VS Code (board type: nrf52840dk_nrf52840) and suddenly board wouldn't respond anymore (LED5 won't light up, isn't accessible through File Explorer or J-Link Commander). Unfortunately I don't remember exactly which hex file I programmed other than it being a Zephyr sample, apologies. Here are the troubleshooting steps I have attempted and their results:
- Does the device show up in Device Manager on your computer? Please try to connect and disconnect the kit a few times. It might show up with unexpected names.
Device does not show up in Device Manager, nor is any USB connection / disconnection sound noticed when plugging and unplugging from the computer.
- Have you tried a different USB cable? Faulty cables are surprisingly often the problem.
Have tried three different USB to micro-USB cables - cable doesn't seem to be the issue since my nrf51-DK works perfectly fine.
- Have you tried using a different computer? If it works on a different computer we know that the kit is not broken and that it is probably a driver issue.
Yes, different computer does not work either - still isn't detected.
- Have you tried to press the IF BOOT/RESET button while power cycling the kit? It should then show up as a Removable Storage Device named "BOOTLOADER". Then you can drag-and-drop the J-LINK interface MCU firmware found here (v170724) onto the storage device to reprogram the JLINK firmware.
Power cycling the kit while pressing the IF BOOT/RESET button in Li-Po/USB does not give any response other than LED1-LED4 blinking very rapidly. Setting power to VDD does not give any response whatsoever. Have also tried switching between nrf ONLY / DEFAULT for the switch at the long side of the board. Thus cannot access the BOOTLOADER folder to recover.
- Have you measured the supply voltage on the kit? It should be somewhere between 2.8V-3.3V. If it isn't, then the hardware is probably broken.
Supply voltage (from VDD to GND) on USB or Li-Po power settings is 2.7V, VDD power setting is 3V.
- Have you made sure that you are using the latest J-Link driver version?
Yes, have already tried updating including completely uninstalling and reinstalling the driver.
- Have you tried this guide? https://devzone.nordicsemi.com/blogs/..
Yes, the board isn't recognized through J-Link Commander so cannot make any connection.
- If on step 4 the kit does not show up as "BOOTLOADER", try to download and install the mbed Windows serial port driver from here: http://developer.mbed.org/media/downloads/drivers/mbedWinSerial_16466.exe
Cannot install driver since no mbed connections were found.
