RE: Unable to flash nRF52840 custom board

Simonr — Fri, 27 Jan 2023 14:20:18 GMT

The error you're seeing is the JLink DLL reporting an error (from the nrfjprog return codes). Usually, the recommended thing to do is to just try again, but I guess that's not working for you. Have you tried using different USB cables, USB ports/hubs to your computer, or a different computer entirely? Do you see the JLink drive under your file explorer when attaching the device via USB?

It could also be the nRF52 custom boards not responding to the debugger, pointing to something being wrong in the HW, and this is (from experience) the most common reason that some custom boards don't respond. Do you mind uploading your schematics and gerber files (as well as perhaps a high resolution image of the physical board) here so we can do a review on our end? I can set the case to Private mode so only yourself and Nordic engineers will be able to see the contents. A normal issue is that the DCDC components aren't mounted, and the device has been flashed with SW that enables the DCDC, this will put it in a bad state that is hard to recover from unfortunately.

It's also common that the pads on the nRF52840 itself aren't soldered properly, so it either isn't powered correctly or has some connection issues. Since 2 of the boards work that does indicate that the schematics/layout is correct, but that there are issues with the assembly procedure...

Best regards,

Simon