I've just printed my first benchy which turned out well except that despite setting up the IR sensor with the piece of belt as instructed the bed is a bit too high so first layer or two are too thin. It was done with hot end #1 on a hybrid Titan dual. The odd thing was that hot end #0 also heated up although I didn't tell it to. If I tell it to heat up on its own nothing happens and I eventually get a heat up fail message. The heater obviously words and so does the sensor. Bad Rumba board?