The nRF52840 is not being recognized, and LED5 is continuously blinking.

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Wed, 12 Mar 2025 16:25:20 GMT

Hi Kenneth,

Thank you for the suggestion, may be I will get back to you soon with the new issue :)

Thank you

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Wed, 12 Mar 2025 16:21:24 GMT

Hi Paka,

That definitely adds to my experience — you're right, nothing happens by mistake.

Thanks

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

PaKa — Wed, 12 Mar 2025 16:03:46 GMT

For the update, if you can't see the device on the PC side even if you try the IF BOOT/RESET option then there is no way to update the device. This as the issue is with the USB interface or the device is somehow broken.

I take for granted you have never connected an external programmer to JLINK as that will cause issues like this (lots of work to do this so won't happen by mistake).

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Wed, 12 Mar 2025 15:53:11 GMT

Hi Paka,

Thank you for the suggestion! I will definitely try all possible methods to confirm if it works by any chance.

Thank you.

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

Kenneth — Wed, 12 Mar 2025 15:40:37 GMT

Hello,

Considering you already working with the nRF52840 I suggest getting:
https://www.nordicsemi.com/Products/Development-hardware/nRF52840-DK
https://www.nordicsemi.com/Products/Development-hardware/nRF7002-EK

Kenneth

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Wed, 12 Mar 2025 15:21:13 GMT

Thank you for your support! Is there any way to flash the board other than using J-Link, perhaps through USB? I will also check with an external debugger.

I am planning to order a new board with WiFi connectivity and came across the nRF7002 DK with the nRF5340 as the host. Would this be suitable for a gateway project? Also, does this board currently support coexistence between WiFi, BLE and Zigbee?

Thank you!

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

PaKa — Wed, 12 Mar 2025 14:01:25 GMT

Before trashing the board maybe toggle all the switches and check the USB connector for physical damage/trash inside. Just to ensure you don't have contact issues anywhere.

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

Kenneth — Wed, 12 Mar 2025 13:28:50 GMT

Okey, then I am sorry to say, but this DK seems broken then. Possible some ESD event or some electrical damage to the board have caused the interface MCU to fail. I don't see any other way that buy a new board, though if you have an external segger j-link programmer you may still be able to problem the on-board nRF52840 IC if it's only the interface MCU that have been damaged.

Kenneth

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Wed, 12 Mar 2025 11:48:18 GMT

Hi Kenneth,

As I already mentioned in the initial query request that I am unable to get the BOOTLOADER drive in file explorer.

Thank you

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

Kenneth — Wed, 12 Mar 2025 10:13:59 GMT

If you press&hold the IF BOOT/RESET during power up when inserting USB cable to the DK, then then you should see a BOOTLOADER drive in Windows, you can try to drag&drop the j-link-ob-sam3u128-v2-nordicsemi-170724.bin you can download from here to see if that helps:
https://www.nordicsemi.com/Products/Development-hardware/nRF52840-DK/Download

Kenneth

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Tue, 11 Mar 2025 16:13:01 GMT

Hi Kenneth,

PCA10056

2.0.2

2021.50

683720887

Please correct me if I am sharing wrong info. FYR I have attached the DK's image.

Thank you.

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

Kenneth — Tue, 11 Mar 2025 12:39:20 GMT

What does the white label on the DK say?

Kenneth

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Tue, 11 Mar 2025 12:13:05 GMT

Hi Kenneth,

I followed the mentioned steps, but unfortunately, I was unable to restore the board to its normal condition. However, the code is still running, but the board is not being detected. I'm really not sure what happened to the dev kit, as it was working smoothly before.

Please guide if at all any hardware side need to be fixed.

Thank you for your support.

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

Kenneth — Mon, 10 Mar 2025 12:22:41 GMT

Hi,

Can you try to download and install the latest nRF Command line tools?
https://www.nordicsemi.com/Products/Development-tools/nRF-Command-Line-Tools/Download

Or nrfutil:
https://www.nordicsemi.com/Products/Development-tools/nRF-Util

Also install segger j-link, for instance v8.10f (currently required by nrfutil when typing, "nrfutil device --version" in command line)
https://www.segger.com/downloads/jlink

Make sure to tick off:

If you still have problems, and with all the things you have already tried with cables and hardware switches, there is also the chance the board have been damaged and you need to order yourself a new DK.

Kenneth

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

AjmalAli — Mon, 10 Mar 2025 10:30:54 GMT

Hi Kenneth,

I have tested with at least four different USB cables and connected the device to multiple laptops. SW9 is set to VDD, and no switches have been changed. In fact, no current measurements have been performed on the development board yet.

Additionally, I am using the older development kit with the PCA10056 onboard debugger, though I am unsure of the exact version.

Thank you.

RE: The nRF52840 is not being recognized, and LED5 is continuously blinking.

Kenneth — Mon, 10 Mar 2025 08:38:52 GMT

Hi,

When LED5 blinks rapidly, it often means the board is not being properly recognized by the computer. This could be due to: Faulty USB cables, USB port issues, Power supply problems, Incorrect switch settings (SW9 should be set to VDD). Maybe you have changed some switches or for instance performed some current consumption measurements where you have cut some solder bridges.

If you have already checked those, then maybe you can tell me which nRF52840 DK version you have?

Kenneth