I have a Arduino Nano 33 BLE that I've been using for a while. I usually upload new programs to the board through USB with the board in a bootloader loop. The other day this stopped working. The board can successfully be put in the bootloader (slow pulsing light), however it does not appear as a TTY device on my computer. The last program I put on my device still works, and successfully outputs serial output (and I can even connect to the bluetooth module).
This leads me to believe my board is working, though I don't understand why I cannot upload via the bootloader. Interestingly the bootloader running makes the board pretty hot (hotter than my program running, is it in an infinite loop or something?).
I thought the bootloader might've been corrupted, so I re-uploaded the board's bootloader via a raspberry pi over OpenOCD (it's possible I did this incorrectly?). Now the device remains in the bootloader no matter what.
I'm wondering if it's possible I fried just the USB part of my board? is that likely? I did hook up the board to a wall adapter that is rated 12V @ 1.5A. The issue seemed to occur after this. Is the board able to handle 1.5A? Do I need to use an additional circuit to properly power the board off of this power adapter?