Custom board not being recognized


I have created a custom board with an NRF52832 chip on. Either programming via ULINK2 or the DK PCA10040 is no succes, board won't be recognized although it is powered.

Checked all support tickets around this subject, and wiring is set up okay including SWCLK, SWDIO, VTG GND. What else can be checked in hardware or wiring what could be the issue?

I have used the reference circuit diagram for the NRF52832 dcdc schematic.