Plugged in yesterday (maybe the day before), powered on, worked fine. Input element 1365 W. Leave to rise for about an hour. switch off. So far, so good. Today I turn it on, after 4 minutes I hear a crack. (such as loud noise) turn off the switch, unplug, and burn marks will appear on the pen. turn it off and I'm sorry. I think the pins are too small for a normal connection.