https://devzone.nordicsemi.com/f/nordic-q-a/65946/unable-to-communicate-with-nrf52840We have a latest set of prototypes which use an NRF52840 on a Laird BL654 module. On two of these protoypes the module is unresponsive. We are using a J-Link Lite module, and nrfjprog to program. I did manage to get one of the two to connect, and ranen-USTelligent Community 13Wed, 16 Sep 2020 11:16:51 GMThttps://devzone.nordicsemi.com/thread/269841?ContentTypeID=1Wed, 16 Sep 2020 11:16:51 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b5438e97-00e4-49b3-b527-78d19d9151deKenneth<p>Hi,</p> <p>Then I don&#39;t really have any good idea other than to check electrically the SWD pins are connected properly (e.g. not swapped) along with GND and VDD. If you have an nRF52-DK that one can also be used instead of the j-link lite to program external pcb.</p> <p>What does it say if you run&nbsp;nrfjprog --version?</p> <p>Maybe check if the reset pin is pulled high (if not try to connect it to VDD).</p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/269830?ContentTypeID=1Wed, 16 Sep 2020 11:01:03 GMT137ad170-7792-4731-bb38-c0d22fbe4515:569ffe6d-155a-4198-8044-98feae4a97c2bgarrood<p>Chip is powered through both VDD and VDDH, tied together.&nbsp; Voltage is 3.3V (verified).</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/269827?ContentTypeID=1Wed, 16 Sep 2020 10:54:53 GMT137ad170-7792-4731-bb38-c0d22fbe4515:e180b2f3-b485-4fdf-86d7-724e216aa7ecKenneth<p>Hi,</p> <p>How do you power the nRF52840 (VDD or VDDH)? The j-link lite only support ~3V if I remember correctly, so measuring VDD may be a good idea.</p> <p>Best regards,<br />Kenneth</p><div style="clear:both;"></div>