https://devzone.nordicsemi.com/f/nordic-q-a/73601/possible-to-disable-pre--and-post-validation-in-the-dfu-processWe&#39;re working on a product that is able to store around 400uC of charge (two 220uF capacitors). There is a constant input of 21 uA minimum coming from a small solar panel. We are using the secure_bootloader example When testing the DFU, the prevalidationen-USTelligent Community 13Tue, 06 Apr 2021 14:13:42 GMThttps://devzone.nordicsemi.com/thread/303215?ContentTypeID=1Tue, 06 Apr 2021 14:13:42 GMT137ad170-7792-4731-bb38-c0d22fbe4515:617c28f9-647a-469f-9164-10f759870ad0Edvin<p>Hello,</p> <p>As I just posted in your previous ticket, you should look into the project settings in sdk_config.h in your bootloader project.&nbsp;</p> <p>&nbsp;</p> [quote user=""]Commenting out postvalidation check (lines 563-569 of nrf_dfu_req_handler) allows the DFU to state it was &quot;complete&quot; but it will fail to boot into the application and advertise as dfutarg.[/quote] <p>&nbsp;Are you sure it is the postvalidation check that causes the issue? It may be the MBR that handles the moving of the image that is drawing the power. I guess you need to experiment with the uECC_verify to figure this out. If the issue is the moving of the new application (from temporary position into final position) then you should look into deleting the old application first and writing the new one directly to the place it will run from. This, however, will only work for application, and not for softdevice updates.&nbsp;</p><div style="clear:both;"></div>