Can't detect nRF52 DK by segger

[tikhop]

The board has been working well.

Since one day, when I try to connect the board with my laptop using micro usb cable, the led5 starts blinking rapidly and I'm unable to program that board anymore.

I've tried to enter into BOOTLOADER mode, the led 5 blinks every second, even though I don't see any connected devices.

What can it be and what does the rapid blink signal mean?

[Einar Thorsrud]

Can you attempt to update the J-Link Interface MCU Firmware? The procedure is described in this post. The nRF52 DK firmware can be downloaded from here.

[Sourabh Barve]

Hi Einar, I tried above solution but it did not work for me. My DK board PCA10040. I programmed the firmware from the second link you shared but still the rapid blinking of the LEd besides the atmel chip has not stopped.

I was trying to program another board of mine using the Dk board.