USBD does work debug out SEShttps://devzone.nordicsemi.com/f/nordic-q-a/36035/usbd-does-work-debug-out-sesHi, I am facing the same problem as in question &#39; USBD don&#39;t work with debugger &#39; from @ Dusautois J&#233;r&#244;me I am trying the same code both on PCA10056 and my board. In PCA10056 works fine but on my board when debugging the USBD driver does not starten-USTelligent Community 13Wed, 04 Jul 2018 12:15:21 GMTRE: USBD does work debug out SEShttps://devzone.nordicsemi.com/thread/138953?ContentTypeID=1Wed, 04 Jul 2018 12:15:21 GMT137ad170-7792-4731-bb38-c0d22fbe4515:42b75aaf-3ddf-4fb6-9486-14c81fa7cf8fMartin Lesund<p>Hi Sebastian,</p> <p>That sounds like a good solution, so it is safe to mark this question as &quot;closed&quot;.</p><div style="clear:both;"></div>RE: USBD does work debug out SEShttps://devzone.nordicsemi.com/thread/138809?ContentTypeID=1Tue, 03 Jul 2018 15:53:56 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b7a41614-90c0-42c4-87c8-0de2254214a8Sebastian<p>Hi,</p> <p>I think I found the solution. Apparently, when code is downloaded first time to the external board MCU, a proper power cycling is required. The reset that the debug out interface is performing is not sufficient and causes the issues described above.&nbsp;</p> <p>The sequence is then:</p> <p>1) Download the code to the external MCU</p> <p>2) Power cycle</p> <p>3) Start debugging</p> <p>This sequence does not &#39;lock&#39; the UDBD initialization.</p> <p>If this is an acceptable answer I can close the question.</p><div style="clear:both;"></div>