I encountered a very similar issue. I designed a custom PCB using the XIAO BLE Sense (nRF52840), but my PCB manufacturer wasn’t able to pre-burn the bootloader before soldering the nRF52840 chip.
After going through this thread, I tried using the nRF Connect for Desktop app, but none of the tools inside could detect any device when I scanned — even with USB connected. I’m wondering, how did you manage to get past this step?
Is it possible to flash the bootloader using only the USB-C connection without desoldering the chip? Any guidance or experience on this would be really appreciated!
Thanks in advance!