https://devzone.nordicsemi.com/f/nordic-q-a/81468/nrf5340-dk-won-t-connect-to-external-hardwareI have an &quot;old&quot; nRF5340-DK which I use to program an external board I am developing. I have no problem with the J-Link/SWD connection to my external hardware using the J19 Debug Out port. However, I recently purchased 2 more nRF5340-DK boards and neitheren-USTelligent Community 13Wed, 10 Nov 2021 07:00:35 GMThttps://devzone.nordicsemi.com/thread/338289?ContentTypeID=1Wed, 10 Nov 2021 07:00:35 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2ddce296-898a-49b8-9114-59f1d4eb803cSimonr<p>Hi Patrick</p> <p>All our DKs are designed for programming external targets at 3.0V VDD. You may be able to program at other voltages but this has not been tested by us and we can&#39;t guarantee or recommend that you do this, or make alterations to the DK to make it work. So please note that this is not a defined or intended behavior on your side.</p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/337987?ContentTypeID=1Mon, 08 Nov 2021 15:55:32 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b7fe496f-27e7-447a-8591-21d3ff5fccefPatGries<p>The external board is running at 1.8V.</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/337930?ContentTypeID=1Mon, 08 Nov 2021 13:31:02 GMT137ad170-7792-4731-bb38-c0d22fbe4515:4b07aec6-b714-4123-8c67-a35d786d0207Simonr<p>Hi</p> <p>What voltage does the external board you&#39;re using run at? Please note that the nRF53 DK only supports debugging at 3V, and that it should work without soldering SB19. The SB19 has a different use in revision 2 than the older nRF5340 DKs, which is why one is soldered and one is open by default.</p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>