Unable to use External J-link debugger with nRF52840-DK

[Jagbir]

I'm having trouble using an external j-link probe (J-Link plus compact) with the nRF52840-DK with Segger Embedded Studio. I am powering the DK from USB (Sw9 VDD) ,using the 10 pin P18 connector on the DK to connect to the J-link plus(20 pin).When I try to "Connect J-Link" in SES it pops with an error saying: "Failed to connect to target. No idcode detected. Please check connection and Target Interface Type". Here is my pin out.

P18_DK         J-link plus side

Pin1    ßà   Pin19(VDD)

Pin2    ßà   Pin7 (SWDIO)

Pin4    ßà   Pin9 (SWDCLK)

Pin6    ßà   Pin13(SWO)

Pin10  ßà   Pin15 (RESET)

Pin3,5,9 ßà   (GND)

I have tried cutting SB60 and shorting SB59 but it did not fix my problem. The on board J-link works fine.

Thanks!

[Simonr]

Hi

Why do you want to use a J-Link probe on the nRF52840 DK in the first place? Please try what pdpro suggested and power the chip using J3 and set the chip into nRF ONLY mode. You can also try programming the chip using nrfjprog or nRFConnect for Desktop to see if the issue persists on multiple platforms.

Best regards,

Simon

[Jagbir]

I don't have enough space on my board that's why I do not want to use an OB debugger.

I was able to program this nRF52840-DK using another nRF52840-DK . However, I am still unable to program this DK using a Segger J-link plus. I have checked my cable connection again, they seem to be fine. I have also tried an external pull up on SDIO line but still it does not work.