https://devzone.nordicsemi.com/f/nordic-q-a/29538/flashing-light-when-connect-my-nrf51-board-with-computerIt worked before when I connected my nRF51 board to my windows 7 computer. The green light is on. But today when I connect them the light is blinking rapidly and there is no connection. In nRFgo studio it shows that &quot;No boards connected&quot;. Any ideaen-USTelligent Community 13Wed, 24 Jan 2018 14:09:06 GMThttps://devzone.nordicsemi.com/thread/117435?ContentTypeID=1Wed, 24 Jan 2018 14:09:06 GMT137ad170-7792-4731-bb38-c0d22fbe4515:85dcb18e-6691-49b2-9b44-2541d21b36f7Bj&#248;rn Kvaale<p>Great! Would you mind upvoting my answer &amp; pressing the check mark please? :)</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/117437?ContentTypeID=1Mon, 22 Jan 2018 20:05:38 GMT137ad170-7792-4731-bb38-c0d22fbe4515:6516c411-8437-456a-8787-dedc399b15dboliverpoc<p>Thanks! It helped!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/117438?ContentTypeID=1Thu, 18 Jan 2018 12:02:45 GMT137ad170-7792-4731-bb38-c0d22fbe4515:c1b21c42-4b6b-42bf-af07-c4ea01b5b937Bj&#248;rn Kvaale<p>Is the LED 5 on your board blinking rapidly? If so, <a href="https://devzone.nordicsemi.com/question/24428/nrf51-dk-board-not-detected/">this case</a> might be helpful. Can you see the JLINK folder under Windows explorer when your DK is attached to the computer and turned on?</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/117436?ContentTypeID=1Wed, 17 Jan 2018 20:33:15 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9bcd8d1b-75cb-47bf-a65f-761f9d63cd0aoliverpoc<p>Also, in my Device Manager it does not show the port at all.</p><div style="clear:both;"></div>