https://devzone.nordicsemi.com/f/nordic-q-a/100417/nrf52833-qdaa-r-boot-lockupGreetings, We have been using the nRF52833-QDAA-R part for a while now in two different products. Same basic architecture. In this product however, once in a blue moon. The nRF52833-QDAA-R does not boot and is locked up. When &quot;locked up&quot;, We seeen-USTelligent Community 13Mon, 05 Jun 2023 13:35:41 GMThttps://devzone.nordicsemi.com/thread/429329?ContentTypeID=1Mon, 05 Jun 2023 13:35:41 GMT137ad170-7792-4731-bb38-c0d22fbe4515:25c152e7-44ea-4036-8056-680b279e0bd4Kenneth<p>Hello,</p> <p>The power on reset circuitry is typically very robust, but if you for instance have a rise time on vdd that exceed the stated max of 60ms then it may not start, ref:&nbsp;<a href="https://infocenter.nordicsemi.com/topic/ps_nrf52833/recommended_op_conditions.html">https://infocenter.nordicsemi.com/topic/ps_nrf52833/recommended_op_conditions.html</a>&nbsp;</p> <p><span>&quot;Note:</span><span>&nbsp;The on-chip power-on reset circuitry may not function properly for rise times longer than the specified maximum.&quot;</span></p> <p><span>If you have a lot of &quot;chatter on supply&quot; when battery is inserted it&#39;s not unlikely this can occur from time to time.&nbsp;A full&nbsp;power cycle is required in such situation. Based on the description and that this occurs rarely I would say it&#39;s likely this is the issue you see.</span></p> <p><span>Kenneth</span></p> <p><span></span></p><div style="clear:both;"></div>