https://devzone.nordicsemi.com/f/nordic-q-a/63187/the-device-is-always-in-dfu-modeI have two devices here, So I combined three HEX files and burned them with JLink, and they don&#39;t behave the same. One starts the application normally, and one is always in DFU mode. Duf can be upgraded over normal air, but still in DFU mode. I also operateen-USTelligent Community 13Tue, 07 Jul 2020 09:34:43 GMThttps://devzone.nordicsemi.com/thread/258766?ContentTypeID=1Tue, 07 Jul 2020 09:34:43 GMT137ad170-7792-4731-bb38-c0d22fbe4515:199d763c-c7a3-40d1-8947-a38437d44d2crun_ar<p>Hi,</p> <p>What mechanism do you use to enter DFU mode? could you be using a pin as input? if so check the state of this pin and make sure it is not shorted to ground/vdd (whatever would make the application stay in dfu mode).</p><div style="clear:both;"></div>