It looks like the fuse contact was not good they were loos and didn’t hold the fuse well got heated and Burned
yes it is the reason. just weld the fuse and it will work just fine
Mine began to burn with awful smell... I was lucky I had a fire alarm that woke me up at 4 in the morning. I had a water heater hooked to it, approx 2700 W of power. They state it is capable to hold up to 3500...
Had the same problem, using it for Water heater, usually sonoff indicates upto 10A, although the water heater is 16A.
it was burnt in the exact same place as previously posted pictures..
it seems like this pcb is not really 16A capable afterall.
happened after approximately 2 months of usage.