I have the ultimaker original plus. I'm having trouble with this. I have the E3D print head, i'm using the ultimaker temperature probe. The 5 volt fan is not turned on, I tried the LED pwm output, no voltage here either. I have a 24 volt 30 mm fan and a 5 volt fan, either one is okay with me. The output for Fan PWM seems to be working okay. I tried the G code " M42 P13 S255 " which does not seem to do anything (No voltage at the LED PWM pins). I'm very grateful for assistance.