Welcome to the SeeMeCNC Community

The last few prints that I have attempted print perfectly for a while, but when I come back in the morning only half of the model is printed, the printer has homed, and I've got def on nozzle and bed, as well as killed on the LCD. I found what I think is a wiring issue with my heater.

I can easily fix the wiring, but I was wondering if the corrosion around the heater is normal, or if I should just clean it off, or if I should be very worried. The corrosion is very easy to see in the picture I attached. Thanks guys!

I would also like to note that Midprint I've seen the reported nozzle temperature on the LED begin quickly jumping between 215, 175, 201, 220, 215, etc.

"killed" just means that the idle timer in the RAMBo fired and it disabled the stepper motors. It's normal behavior.

Your thermistor lead is right on the edge of being able to short against the heater block - you might want to slide the ptfe tubing up a bit higher on the leads. The oddly changing hot end temps are indicative of a loose wire or a short involving the thermistor.

g.