nRF52840DK COM port does not appear

RE: nRF52840DK COM port does not appear

Elfving — Wed, 14 Feb 2024 10:29:47 GMT

No problem Lukas! 🙂

Please let us know if there is anything else.

Regards,

Elfving

RE: nRF52840DK COM port does not appear

zazas321 — Wed, 14 Feb 2024 10:11:12 GMT

[quote userid="103347" url="~/f/nordic-q-a/108298/nrf52840dk-com-port-does-not-appear/468767"]I see that you have some cables connected up to the current measurement pins there, and have presumably cut SB40. I am not sure if you would be able to connect to the debugger with that connected. Could you try disconnecting those cables, and use a jumper on the current measurement pins and see if it helps?[/quote]

That is a jumper (I did not have a proper jumper so just used a cable instead), see the full screenshot below:

Going through the list if things to try as you have suggested:

1. Does the device show up in Device Manager on your computer? Please try to connect and disconnect the kit a few times. It might show up with unexpected names.

Nothing shows up on Device Manager.

2.Have you tried a different USB cable? Faulty cables are surprisingly often the problem.

Yes. Same problem

3.Have you tried using a different computer? If it works on a different computer we know that the kit is not broken and that it is probably a driver issue.

Problem is definately with the nRF52840DK as I have borrowed another nRF52840DK from colleague and tried with my PC and my USB cable and it works as expected. My broken DK does not work on any other PC'S.

4. Have you tried to press the IF BOOT/RESET button while power cycling the kit? It should then show up as a Removable Storage Device named "BOOTLOADER". Then you can drag-and-drop the J-LINK interface MCU firmware found here (v170724) onto the storage device to reprogram the JLINK firmware.

Problem fixed!!! After reprogramming the interface MCU the interface LED (led5) started blinking and after the reset the COM port appeared and I can use the device as usual.. Thanks!

RE: nRF52840DK COM port does not appear

Elfving — Wed, 14 Feb 2024 09:56:17 GMT

Hello Lukas,

First of all, there are multiple things that might be wrong. Have a look at this list here of things to try.

[quote user=""] I may have accidentally connected Li po battery terminals the other way around for a brief moment, also, I may have supplied around 4.0V via the External supply connector (I think the maximum voltage is 3.3V).[/quote]

I don't think that should be enough to fry anything.

I see that you have some cables connected up to the current measurement pins there, and have presumably cut SB40. I am not sure if you would be able to connect to the debugger with that connected. Could you try disconnecting those cables, and use a jumper on the current measurement pins and see if it helps?

Regards,

Elfving