After successfully printing on my Taz for a couple months, the extruder head has stopped heating at all. I tried measuring the voltage on the hot end connector on my board (I read that it should show about 12 V). My voltage meter is showing 0 voltage at the connector when I tell the hot end to heat. My print bed heats perfectly (and the print bed connector reads 11.5 V at the board). Does this mean my Rambo is damaged?