I had same issue with my macbook air. No boot and no charging. SMC reset didn't work. Unpluging charger and heating with dryer didn't work either. The solution was to open it up, unplug the battery from main board, wait half an hour and I could boot macbook. I noticed that battery was already 40% charged when it started up again, so macbook not being able to start was not due to low battery. It was due to some kind of crash or soft malfunction which entirely prevented macbook from booting until battery was unplugged from motherboard.