if you use a electrically conductive thermal paste on a direct boded star, will it go DD and bypass the driver?
The thermal pad of an XM-L is potential free, so if you did not short on of the wires to the star (or use an exotic LED with non-neutral pad ;-)) by accident, it should also be.
In short - no 
hmmm... must have done a bad reflow and one of the pads on the xml2 shorted i am guessing then...
tried two drivers last night, and both are high only and puts some heat OTF
Have you maybe contact to the + and - symbols on the star with your wires?
I remember them to be connected to the metal on some stars.
Or maybe one wire has damaged insulation and shorts with the star, happens easily on the edge where they go down to the driver.
no, both drivers were new and un damaged. it is a noctigon xm star... i will do some continuity tests on one right now. should have thought about that first
edit: no continuity between center pad and +/-. must have used too much solder and shorted out to the center pad. only thing i can figure. it was my first reflow and used solder, not solder paste
How can it be bridged if there's no continuity between +/-/gnd?
+ or - on the emitter could have bridged to the center pad. i will pull it out tonight and check it out. i will bet i will have continuity between either + or - to the bottom of the noctigon