DK91 debugger and USB debugger detection issue, windows 11

[phil38]

I am experiencing an issue with my nRF915DK board. When I connect the board to my PC via USB, the debugger LED blinks continuously.

I have the same issue with a nrf52840DK.

I'm using a JLink_V7.94i driver.

I had try to use different USB cable

[phil38]

Note, the serial number (i.e 1051288714)  is displayed in vs code 

Thanks in advance , Philippe

[Priyanka]

Hi,

Are those boards both new?

Have you flashed any sample on them previously?

Could you try setting the device in Bootloader mode?

Regards,

Priyanka

[phil38]

These have been already used, and flash with some sample.

Here is the log I had when I open the DK9151 with tthe Nrf Programmer

2025-06-06T11:59:02.492Z INFO Using the bundled core version for nrfutil device: 8.0.0
2025-06-06T11:59:03.166Z INFO Using nrfutil-device version: 2.6.4
2025-06-06T11:59:03.166Z INFO Using nrf-device-lib version: 0.17.35
2025-06-06T11:59:03.166Z INFO Using nrfjprog DLL version: 10.24.2
2025-06-06T11:59:03.166Z INFO Using JLink version: JLink_V7.94i
2025-06-06T11:59:03.542Z INFO Getting serial port options from the persistent store for 001051288714.pc-nrfconnect-programmer
2025-06-06T11:59:03.543Z INFO Getting serial port options from the persistent store for FTC9QOG6.pc-nrfconnect-programmer
2025-06-06T11:59:06.182Z INFO Selecting device with the serial number 001051288714
2025-06-06T11:59:07.799Z INFO Selected device with the serial number 001051288714
2025-06-06T11:59:07.799Z INFO Using nrfutil device to communicate with target via JLink
2025-06-06T11:59:09.298Z INFO Reading readback protection status for Application core
2025-06-06T11:59:09.299Z ERROR Failed "reading readback protection status for application core". Error: code: 1, description: Generic, message: Batch task protection-get failed, [Probe] Emulator error: No emulator with connection info 'Usb(JLinkSerialNumber(1051288714))' was found
2025-06-06T11:59:09.619Z ERROR Error: Failed with exit code 1.
One or more batch tasks failed:
- [Probe] Emulator error: No emulator with connection info 'Usb(JLinkSerialNumber(1051288714))' was found, code: Generic.
Message: Batch task protection-get failed, [Probe] Emulator error: No emulator with connection info 'Usb(JLinkSerialNumber(1051288714))' was found.
2025-06-06T11:59:18.113Z INFO Getting serial port options from the persistent store for 001051288714.pc-nrfconnect-programmer