JLink returns DLL error.

[JJK]

I am working with a custom board and the nRF52840.  I have been able to program various hex files to the Nordic chip on this board using SWD and an official Segger JLink device.  Now when I try to program the chip I get this error.

Here's the log

I've seen similar problems on the Dev site but no answers.

I've updated to the most recent version of JLink.  I've tried using the Segger command prompt and it will not connect to the device either.  Erase doesn't work since the JLink can't establish a SWD connection.  Any ideas on what to try next?

[JJK]

I've tried two different JLink debuggers and a nRF52840-DK to program it. I changed the ribbon cable for the debugger and the USB.

[JJK]

I scoped the swd with a logic analyzer.

These are from the test points on the board.  There are a bunch of NAKs at the end that most likely correspond to the not connected message in the log file.

[Vidar Berg]

Can you think of any reasons as to why suddenly starts to fail on all boards? Recent SW changes, etc.. I would also be useful to know if you have tried on more than one computer and if you've been attempting the '--recover' option in nrfjprog?  

[JJK]

'--recover' doesn't work.  There is no connection.  I can program a 52840-DK with the computer using the command line tools which makes me think it is the hardware but to have them all fail simultaneously is very odd.  There was a windows update that coincides with the issue I'm having.  

[Vidar Berg]

How are the custom boards powered? Is it possible to power it from the 52840 DK, then use the OB jlink on DK to program the board?