'Recovery Failed. Unknown error' nRF52 DK

I have open a brand new nRF52 Development Kit. It is not recognise by the nRFgo Studio. I have tried the trick you mention on this thread:

https://devzone.nordicsemi.com/f/nordic-q-a/27216/nrf52832-can-not-be-recovered

without lack. I did flash the lastest nRF5x-OB-JLink-IF version 170724. After this trick the dev kit is updated to the latest segger firmware v22g but the recovery still gives an error. 'Recovery Failed. Unknown error'.

Any help most welcome