I had just assembled my RepRapPro Huxley last week, which came with a Melzi 2.0 board. I had been unable to get anything to really print decently even after setting the e steps and trying a bunch of different hot end and bed temperatures, so I tried using a cooling fan to see if it helped. I wired a standard 80mm computer fan to the board's fan connector and this is what happened:
The hot end heated up to the printing temp, when for some reason the fan attempted to kick in, which caused to board to momentarily power off, as if I had bumped the power cord. I had pronterface reconnect with the printer, set the hot end temp back up, but the hot end dropped in temperature and now no longer heats up. The multimeter reports that the heater resistor's resistance seems to have increased by about 1.6 million ohms.
I'm not sure what happened here.
The hot end heated up to the printing temp, when for some reason the fan attempted to kick in, which caused to board to momentarily power off, as if I had bumped the power cord. I had pronterface reconnect with the printer, set the hot end temp back up, but the hot end dropped in temperature and now no longer heats up. The multimeter reports that the heater resistor's resistance seems to have increased by about 1.6 million ohms.
I'm not sure what happened here.