This is my 10th build, 4th Nano biscotti and this the first time this has happened.

I have a tri-Cree RB,RB,W, Nano biscotti, and 18650 battery

Wiring is per usual: positive battery to charge port, board and + of LED
L1 on board to .5 ohm 3W then on to the - pad of both RB of the tri-cree
L2 on board to a 1 ohm 2W then to the - pad of the W

Board boots, activate and in 3 seconds the .5 ohm resistor is blazing hot and smoking.

Any thoughts? I am at a complete loss as to what’s going on.