I plugged the battery in backwards( I forgot to check polarity) and now the unit just shows a red light steady on. After a while it blinks really fast. When I plug the unit in via usb it shows the COM port for about 4 seconds then goes away until next power cycle. Pushing the reset button does nothing and will not show dfu mode. I would assume the unit is dead?
I have a multimeter. I can probe the board if someone can help. Thanks.
RAK4631
Welcome to RAK forum @Tesla747 ,
The extent of damage of the reverse battery cannot be determined easily regardless if it still works. If you connect it that way in a couple of seconds, there can be damage in the power stage - charger and/or regulator. But it can also damage the core.
To preserve the core, I highly recommend not attach the core on the base. You can probably still measure 3.3V since the core still shows as COM port. But nonetheless, there is no guarantee that the module/s are still in tiptop condition.
What are my options? Can I still power the unit without the baseboard?