Hi, I have the same problem with my max, mains is on but the inverter is not detecting it. I opened her up and found a fuse (63LET) on the main AC in. Its kind of strange that it is rated for 63A and it popped, thats about 15kW. the breaker 40A did not trip. So I suspect that it is some sort of transient which the fuse cleared within one cycle, where the breaker needs two or three cycles to trip. Anyways here is a couple of pics.