SEGGER J-Flash lite flash to nRF 52840DK using J-link Plus connected to P18 Debug In ERROR: Could not connect to target

[Truong Nguyen]

Hi, I'm trying to flash .hex file using J-FLash lite to nRF52840DK board using P18 Debug In (by SWD Interface). 

I'm aware of pin out of J-Link Plus for SWD from https://www.segger.com/downloads/jlink/UM08001 

The connection between P18 and J-Link as follow: https://devzone.nordicsemi.com/f/nordic-q-a/55575/unable-to-use-external-j-link-debugger-with-nrf52840-dk

P18_DK         J-link plus side

Pin1    -   Pin19(VDD)

Pin2    -   Pin7 (SWDIO)

Pin4    -   Pin9 (SWDCLK)

Pin6    -   Pin13(SWO)

Pin10  -   Pin15 (RESET)

Pin3,5,9 -   (GND)

Screenshot of ERROR:

Any suggestion to solve this problem?

[dstarling]

Why not use the onboard debugger to program the chip?  Also it appears the referenced article about P18 and J-Link above had some problems too?

[Truong Nguyen]

Hi, the reason for not using onboard debugger is because my final product just only uses the Chip, not the entire dev kit. So I plan to use J-Link plus to flash the firmware into it. 
And yes, I noticed there is still problem with that article so I just tried it out to see.

[Jørgen Holmefjord]

Hi,

Have you powered the DK externally or through USB?

Best regards,
Jørgen

[Truong Nguyen]

Hi Jorgen, I can power up the DK through J-link Plus using J-link Commander: "power on". I could enable Boot loader mode by pressing Boot/Reset button while power it up and the LED5 will blinking in slow pace.

By plugging USB cable from laptop to J2, I can manage to flash .hex file into the chip using J-Flash Lite.  

The J-Flash can detect both onboard J-Link and external J-Link Plus connected to P18.

However, when I used external J-link Plus to power up the board ( the board can be powered up) and then tried to flash .hex file into the chip, it showed me "Could not connect to target".

So my doubt is whether the pin diagram of P18 (Debug in) for SWD interface (as posted above) is correct?

[dstarling]

It may be that the external J-Link cannot supply enough power.  Did you try to switch the "nRF only switch" SW6 to disconnect the nRF52840 from the onboard debugger?  Otherwise you may still need to verify the power is sufficient?