We are encountering a very strange situation. We have two custom PCBs (PCB1 and PCB2) both with an NRF52832. We were able to program both PCBs (multiple times) with the JLink Ultra+, JLink EDU and Jlink EDU Mini without any issues, until recently (quite likely after Jlink firmware upgrade). There was a gap of 3-6 months between last programming PCB1/2 and trying to program them recently with exactly the same hex file and no code protection.
Issue with PCB1:
We are now unable to program with the JLink EDU Mini using nrfjprog.exe (ERROR: JLinkARM DLL reported an error. Try again. If error condition...), nor using jlink.exe (Cannot connect to target after InitTarget() start/end a few times). I.e., JLink EDU Mini cannot detect the NRF52832. We can still program with the JLink EDU and JLink Ultra+. Why?
We installed the latest version of nRF Command Line Tools (10.14.0) but it is still the same (JLink Ultra+/EDU OK, JLink EDU Mini not OK).
We installed the latest version of Jlink Software (7.54a) but it is still the same (JLink Ultra+/EDU OK, JLink EDU Mini not OK).
We even downgraded to nRF Command Line Tools 9.8.1 (which DID NOT downgrade the Jlink EDU Mini's firmware) and still the same (JLink Ultra+/EDU OK, JLink EDU Mini not OK).
Issue with PCB2:
We are unable to connect to the NRF52832 with ANY JLink (Ultra+, EDU, EDU Mini) even by doing everything as mentioned with PCB1. As with PCB1, we were able to program it over and over before without any issues, but not recently. We even used different JLink Ultra+, EDU, EDU Minis, and also different laptops, and with different PCB1s and PCB2s.... all the same result.
What's going on? We strongly suspect it is JLink FW issue and we are posting here as well as Segger's forum. Hopefully some of you have (unfortunately) encountered this before and have a solution. Also,possible to downgrade JLink's FW?
