Segger J-Link 5.02h not working on nRF52 (PCA10400) development board

[rugarcia]

Hi, I upgraded the Segger J-Link software from 4.98c to 5.02h. I did this because I was getting some windows pop ups when starting Master Contol Panel on my nRF51 dongle. I fixed the issue with the nRF51 dongle but now my nRF52 dev board has having a problem when I connect and try debugging or flashing using Keil Uvision V5.16a. I get the following errors:

• No Cortex-M SW Device Found followed by
• Error: Flash Download failed - Target DLL has been cancelled

In Keil Uvision under Options->Debug window I have the "J-Link/J-Trace Cortex" selected

• When I click on the "settings" button I can see the J-Link serial number
• I have selected Port SW.
• I do not see any entries in the "SW Device" box

[Susheel Nuguru]

i just tried with the version you mentioned, it worked just fine. Something is wrong with your installation.

[rugarcia]

I guess I'll try and re-install the Keil uVision 5 again and see if it fixes my problem. Thanks Aryan

[rugarcia]

I measured the nRF52 voltage and it was at 0.8V!!

I was using this dev board to measure current and I had cut a trace that isolated the nRF52 power. Under normal conditions I have this connected my SMU ammeter. I just realized that the SMU was powered down and therefore not able to close the circuit. After enabling the ammeter or shorting the current measure pins I can communicate with the device and flash it.

Problem solved!

[bvuong87]

Thanks for posting this! It saved me the other day too, after I spent too much time looking at overly complex solutions to my problem