https://devzone.nordicsemi.com/f/nordic-q-a/101669/how-to-troubleshoot-and-diagnose-j-link-connection-and-usb-dk-board-power-on-errorshi all, Hello, my board(nrf5340 dk,pca10095,0.11.0,2020.45 and nrf52840 dk ,pca10056,1.0.0) often encounters the issue of &quot;J-Link not found&quot; (no LED(LED3)/USB not mounted). Alternatively, it initially works correctly for debugging and programmingen-USTelligent Community 13Mon, 17 Jul 2023 09:41:10 GMThttps://devzone.nordicsemi.com/thread/436680?ContentTypeID=1Mon, 17 Jul 2023 09:41:10 GMT137ad170-7792-4731-bb38-c0d22fbe4515:cf47dd30-de54-49ff-849f-60d2f9331843Kenneth<p>We are not aware of any issues, but recommend to take some ESD precautions when handling the kits. There should be a date code printed on the label also, I believe the v1.1.0 kit must be from 2019 or older? There will be some wear and tear when used for development for many years.</p> <p>Kenneth</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/436309?ContentTypeID=1Thu, 13 Jul 2023 15:15:52 GMT137ad170-7792-4731-bb38-c0d22fbe4515:841c8f2f-c848-4d0d-b4f3-d30453b11c283Rsteven<p>HI nordic,</p> <p>Thanks for your response.<br />In addition, I have another version of nrf52840&nbsp;<span>pca10056,1.1.0</span> dk which also has problems.<br />The following is the comparison (TP, test pin,A is normal; B is&nbsp; abnormal)</p> <p>A&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp;----------------&nbsp; &nbsp; &nbsp;&nbsp;B<br />------------------------------------------------------------------------------------------------------<br />3.0v&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; TP29&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;2.8v</p> <p><span></span></p> <p><span>------------------------------------------------------------------------------------------------------</span><br /><br /><br />3.0/4.6v&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;TP30/TP32&nbsp; &nbsp; 0.5/4.9v</p> <p><span>------------------------------------------------------------------------------------------------------</span><br /><br />4.9v&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;TP36&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;4.9v</p> <p><span>------------------------------------------------------------------------------------------------------</span><br /><br />2.8v&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;TP35&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.0v</p> <p><span>------------------------------------------------------------------------------------------------------</span><br /><br />1.4v&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;TP34&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.4v</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/435437?ContentTypeID=1Mon, 10 Jul 2023 09:46:48 GMT137ad170-7792-4731-bb38-c0d22fbe4515:a3dcfa8c-20c3-4c27-b9da-63cac21c9841Kenneth<p>Hello,</p> <p>This doesn&#39;t sounds good at all, the DK should be drawing in the tens of mA, this should not cause any USB power issues.</p> <p>Do you have a second DK for comparison, have you measured the current drawn, I recommend to order yourself a new DK.</p> <p>Edit: I can see you are using a preview kit (v<span>0.11.0), please get a new one.</span></p> <p>Kenneth</p><div style="clear:both;"></div>