https://devzone.nordicsemi.com/f/nordic-q-a/72513/smp-server-sample-drops-connection-with-custom-board---crystal-config-issueHi there, I am running a custom board based on the nRF5340-DK. It&#39;s a minimal board, notably with both oscillators It seems to behave itself with low-rate BLE use-cases (eg. HRS, example), but I am struggling to perform a DFU using the Zephyr SMPen-USTelligent Community 13Tue, 09 Mar 2021 12:44:37 GMThttps://devzone.nordicsemi.com/thread/298703?ContentTypeID=1Tue, 09 Mar 2021 12:44:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:52c7d300-d1e8-4cf2-ab81-aab012221cc6ketiljo<p>Have you set the load cap values for the crystal in UICR? The value will be dependent on the CL value of the crystal as Ccap = CL * 2 - Cpin, where Cpin = 4 pF. For a crystal with CL = 8 pF, set the load caps to 12 pF.</p><div style="clear:both;"></div>