No connection with nRF52840 DK from PC via USB (J2)?

[KPC_Lunav]

Hi,

I saw a similar post (Case ID: 249969) and this just happen to me.

I have not used my nRF52840 DK for a few weeks. It has been in its original plastic bag the whole time. Connected it today and nothing happen (no light on LED5), no responds from Windows that it connected. I also plugged in a nRF52 DK on the same USB cable and that "turned" on, LED blinking and I could connect to it with the nRF Connect application (v3.3.3) and programer v1.4.2.

made sure it was like below:

I checked power on TP11 and TP12 - found 5V as expected. I also checked other TPs and found 3.19V (TP31) and 4.65V (TP32).  Also measured 2.98V on VDDnRF and same on TP7.

So I'm very curious on what has happen with my nRF52840 DK?

Could it be something wrong with the interface MCU? IF BOOT/RESET button?

Any suggestion would be appreciated.

best regards,

Peter 

[Simonr]

Hi

Okay, try the following:

1. Download the MCU firmware (.bin file) from the DK's download page if you haven't already.

2. Hold reset button and power on the DK.

3. You should see a "bootloader" drive on your computer, insert the .bin file in this drive. Do not put any other files here!

4. Let the interface MCU flash itself. It should reconnect as a J-Link, and be usable again.

PS: This will happen if you hold the reset button on DK power-up, so that might be what has happened.

Best regards,

Simon

[KPC_Lunav]

Hi Simon,

Well that was magic... followed your steps and the bootloader driver popped up (although with a name like "mbed" or similar). Dropped in the J-LINK OB .bin file I had downloaded and after restart the JLINK (D:) drive popped up and I can see and reach the DK in the nRF Connect app such as Programmer and BLE tool.

Thanks for all the help.

Peter

[Hareesh]

Hi Peter, Hi Simon 

My nrf52840 is new and is not getting detected in my laptop. Yesterday LED5 and LED1 were pulsating. Today when I connected my board , nothing is blinking. Also, when I remove the usb cable from the board, the LED1 is blinking and LED5 is pulsating for few seconds. please help me in solving this issue.

Regards

Hareesh

[Simonr]

Hi Hareesh

What are the various switches set to on your DK? I'm guessing that your nRF power source is set to LiPo and not VDD.

If none of the suggestions in this case help, please create a ticket of your own where you describe your problem and we will try to help you out.

Best regards,

Simon