I have an M5 I purchased in December of 2014 it came with the transport case and I've probably used it a total of 15 times. I just went on a shoot today and it's not turning on. No green LED's, nothing. I have checked everywhere and have not found any instances of this happening before aside from possibly an overheating issue. It was in the trunk of my car for approx 2 hours today but it was not in any kind of oppressive heat (it was 76 here in SC today and I was parked in the shade). I checked all my connection seatings and everything seems to be tight, including unscrewing the on/off switch panel and checking behind there. I have another shoot tomorrow and am in desperate need of your help. Has anyone else had this issue?