RE: NRF5340 DK Cannot be recognized

Øyvind — Tue, 14 Jul 2026 06:51:56 GMT

Could you please provide some more details on how you were using the board prior to it stopping? Did you try programming anything special when it stopped?

Are you able to provide a picture of you board, both front and back?

[quote user=""]How can we solve this problem?[/quote]

I fear that there is not much we can do. When LED5 (the interface MCU LED) doesn't light up and no J-Link device appears in Device Manager, this typically points to an issue with the interface MCU (IMCU) rather than application MCU.

You might need to reach out to your local sales representative or the distributor where you got the board in order to replace it.

Steps to Try

Power cycle the DK – Disconnect USB, wait a few seconds, and reconnect. This is the first fix for MSD-related unresponsiveness. [MSD issues]
Try different USB cables and ports – Use a known-good USB cable and a different USB port or computer.
Try the IMCU bootloader mode – Press and hold the IF BOOT/RESET button (SW5) while plugging in the USB cable to force the interface MCU into bootloader mode.
Recover using nRF Util – If the board is partially detected, you can attempt recovery:
- Download nRF Util and install the nrfutil device command.
- Connect the DK and run:
  
  nrfutil device recover
- Disconnect and reconnect the DK. [nRF Connect troubleshooting]
Check for readback protection – On the nRF5340, APPROTECT requires firmware to explicitly enable debugger access after every reset. If no firmware is present to unlock it, the nrfjprog --recover (or nrfutil device recover) command handles the ERASEALL via CTRL-AP automatically. [Debugger access blog]

Let me know how this works for you.

Kind regards,
Øyvind

RE: NRF5340 DK Cannot be recognized

Neo Yang — Tue, 14 Jul 2026 01:08:00 GMT

I tried replacing the USB data cable, but it didn't work. The P22 was not removed.

RE: NRF5340 DK Cannot be recognized

Øyvind — Mon, 13 Jul 2026 12:06:52 GMT

Hello, are you able to test with another USB cable to exclude issue with cable? Have you removed the jumper on nRF Current Measurement (P22)?

Kind regards,
Øyvind