nRF24LU1P firmware update trouble

[Alessio]

Goodmorning,

we are trying to update the firmware on a nRF24 development kit board (nRF2727) that was programmed with the PTX sample from your software development kit.
The USB is unresponsive due to the non support of it from the firmware.
We are trying to update it through SPI but as soon as we tie the PROG pin to the VDD the VDD line drop to 0. What can the problem be? We already program the other PCB (nRF2726) through SPI without problems.
Is there any way to update that device or reset it to the default and than update it?

Thanks.

[Kenneth]

This was weird. The PROG pin is an input pin (typically pulled low by an external pull down resistor), and it does not make sense that this should have any impact on VDD. Think you need to refer to chapter 17.7 in the nRF24LU1+ datasheet, and check that electrically all pins are connected as expected.

Best regards,
Kenneth