https://devzone.nordicsemi.com/f/nordic-q-a/55816/pca10056-pdk-is-dumb-nowHello, I accidentally set my board in boot mode and then lost power, then after power on again, the board seems in a total dumb mode: invisible in Device Manager, LED5 is always off, can&#39;t be accessed by nordic command tool. I have tried holdingen-USTelligent Community 13Thu, 19 Dec 2019 23:41:33 GMThttps://devzone.nordicsemi.com/thread/226454?ContentTypeID=1Thu, 19 Dec 2019 23:41:33 GMT137ad170-7792-4731-bb38-c0d22fbe4515:f0806a76-749d-4341-99bb-afc5cbbeb14fDanielDuan277<p><span>Hi Simonr,</span></p> <p><span>I re-flashed the interface mcu bootloader and now it works.</span></p> <p><span>Thank you!</span></p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/226449?ContentTypeID=1Thu, 19 Dec 2019 21:09:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:1bc9f484-b19f-4518-b936-ebc44f715f83DanielDuan277<p>Hi Simonr,</p> <p></p> <p>No JLink window pop up when connected with computer and power it on.</p> <p></p> <p>Cheers.</p> <p></p> <p>Daniel Duan</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/226329?ContentTypeID=1Thu, 19 Dec 2019 10:26:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:efa9dac3-d836-4fd4-a812-f3f9ef7a5560Simonr<p>Hi</p> <p>Does the JLink window pop up when you connect it to the computer and power it on? If so, you should be able to drag and drop the MCU firmware file (<a href="https://www.nordicsemi.com/Software-and-tools/Development-Kits/nRF52-DK/Download#infotabs">downloadable here</a>) to the drive that opens when you power up the DK in order to get the standard firmware back onto the debugger MCU.</p> <p>Best regards,</p> <p>Simon</p><div style="clear:both;"></div>