https://devzone.nordicsemi.com/f/nordic-q-a/108109/high-ble-fail-rate-on-custom-nrf5340-boardHi all, I have a batch of eight custom boards based around the nRF5340. Three of them work flawlessly, and the rest have assorted digital communication issues, BLE issues, or both. One board can&#39;t even initialize the BLE radio. When calling bt_enableen-USTelligent Community 13Wed, 07 Feb 2024 13:40:07 GMThttps://devzone.nordicsemi.com/thread/467937?ContentTypeID=1Wed, 07 Feb 2024 13:40:07 GMT137ad170-7792-4731-bb38-c0d22fbe4515:8d57450c-1735-4895-93dd-c3460a9180fbKenneth<p>Hello,</p> <p>If you haven&#39;t already you should make sure you have followed:<br /><a href="https://devzone.nordicsemi.com/guides/hardware-design-test-and-measuring/b/nrf5x/posts/general-pcb-design-guidelines-for-nrf53-series">https://devzone.nordicsemi.com/guides/hardware-design-test-and-measuring/b/nrf5x/posts/general-pcb-design-guidelines-for-nrf53-series</a>&nbsp;</p> <p>short story; copy the layout exactly is the safe bet.</p> <p>Once you have the hardware populated you should run the radio test to confirm the board operated as intended:<br /><a href="https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/peripheral/radio_test/README.html">https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/samples/peripheral/radio_test/README.html</a>&nbsp;</p> <p>short story; measure the output power and carrier frequency on a spectrum analyzer.</p> <p>In terms of the failure you see in specific, you may try to use the internal RC for the 32kHz as specified here:<a href="https://devzone.nordicsemi.com/f/nordic-q-a/100610/bt_dev-drv--open-fails-with-bt_hci_driver-bt_rpmsg_open-endpoint-binding-failed-with--11-error"><br />https://devzone.nordicsemi.com/f/nordic-q-a/100610/bt_dev-drv--open-fails-with-bt_hci_driver-bt_rpmsg_open-endpoint-binding-failed-with--11-error</a>&nbsp;&nbsp;</p> <p>Kenneth</p><div style="clear:both;"></div>