Bricked debugger on nRF54L15-DK

[Nick Stoughton]

I just received a new 54L15DK and was attempting to port a simple 5340 project to it. The first time I attempted to flash it, it _looked_ like it was successful:

[10/10] Generating ../merged.hex
-- west flash: using runner nrfutil
-- runners.nrfutil: reset after flashing requested
Using board 001057782011
-- runners.nrfutil: Flashing file: /home/nick/work/eargo-charger-fw/projects/novum/build/merged.hex
-- runners.nrfutil: Erasing pages touched by firmware
-- runners.nrfutil: Programming image
-- runners.nrfutil: Verifying image
-- runners.nrfutil: Reset
-- runners.nrfutil: Board with serial number 1057782011 flashed successfully.

However, from this point on, the debugger refuses to accept commands. I suspect I flashed the debugger (a 5340) rather than the 54L15, since I had not fixed my sysbuild.conf. Is there any way to reflash the debugger?

--

Nick

[PaKa]

You are not able to program the debugger that way so that is not the issue here. Trying to reprogram that device will most likely brick your board permanently so don't try it! Check all power supplies voltages on the nRF54L15 (all decoupling caps) and post here with a picture of the board.

What version is this of the DK? Are any of the LEDs lit up?

[Priyanka]

Hi Nick,

Unfortunately it's not possible to reflash the debugger. But it's also pretty difficult to brick it (As mentioned by Paal).

Could you try nrfjprog --recover or nrfutil device recover?

Also, could you share what error occurs when you try to flash? And also please share the pictures too.

Regards,

Priyanka

[Nick Stoughton]

I have attempted both recover mechanisms, but it just says 

 - [Probe] Timed out waiting for response from worker. (Generic)

VBUS is 5.2v, VDDIO is 1.75v 

[Nick Stoughton]

Aha! After leaving it switched off for 12 hours, nrfjprog --recover finally worked! Thanks! All is now working...

[PaKa]

The green LED lit up on the picture shows the debugger is powered up and code is running, blinking pattern tells you what issue you may have so good tip is to report that as well if you see issues.