Hi,

I have just acquired an NRF52840 Dongle (nrf52840_pca10059) and I am facing some difficulties with board startup.

When I flash a zephyr binary to the board (e.g. samples/basic/blinky) the board starts up fine and starts the application.
But when I disconnect the board from USB power and reconnect it, the application no longer starts (and the internal DC-DC converter does not seem to start-up either).

If I run no-op pyOCD command (e.g. pyocd-flashtool -t nrf52840) the application springs to life (e.g. for blinky, the LED starts to blink).
I am not using mcuboot or any other bootloader; just the bare-bone sample application.

What am I missing here?

Best regards,
Brix
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Henrik Brix Andersen