I don't know about this case. Test button fires it, so batteries are surely oriented correctly. Sometimes the problem is that the flash is not inserted deep enough into the hot shoe, not making contact with the foot pin. But if in hot shoe and turned on, it ought to trigger with shutter button. You could test for a foot defect, by using a metal paper clip or a screwdriver blade (off camera), to short the foot pin to the metal foot frame. It should fire. Won't hurt anything, shorting that pin is how it is triggered. The shutter shorts that pin on the hot shoe. (and the flash tube can get hot, so do NOT lay it face down on anything that could scorch. Aim it out away from you in the clear.)