MicroPython Forum (Archive)

I accidentally plugged in the positive terminal of a 9v battery to 3v3 instead of V+ and now the red, yellow, and blue LED's are continuously shining when I give it power. The board doesn't show on the PC as a removable device and I can't connect to it through serial. I have a pyb 1.1. Help please!!

I'm afraid it sounds as if you have. I can only think of one thing left to try, which is to see if you can flash new firmware, but given the symptoms I don't hold out much hope