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

[AjmalAli]

Hi,

I have been using the nRF52840 for a long time, and everything was working fine. However, now LED5 starts blinking whenever the USB is connected to J2. I have tried several methods, such as uninstalling and reinstalling J-Link, but the issue persists.

Additionally, when I press the BOOT button and power cycle the board, I do not see any bootloader folder in the file explorer. I have also tried changing the USB cable, but that did not help.

I am not sure what to do next. Please help me resolve this issue.

Thank you.

[Kenneth]

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

[AjmalAli]

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.

[PaKa]

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.

[AjmalAli]

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!

[Kenneth]

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

[AjmalAli]

Hi Paka,

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

Thank you. 

[PaKa]

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).

[AjmalAli]

Hi Paka,

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

Thanks