Hotend cooling fan cools down the top part of the hotend (heatsink) from the heat which is transferred from the heater block. It always starts up when hotend temperature reading reaches 50°C and spins for the whole duration of the print! If the fan is not functioning, you can expect the nozzle to jam after the first few layers.
Power down and unplug your USB cable if connected. Open the electronics covering and examine the wiring diagram.
Check the following:
You can easily test the nozzle hotend fan function from the LCD menu Preheat - PLA. When the hotend temperature reaches the 50°C, the fan should immediately spin up.
If the fan doesn't spin up, you can unplug it from the electronics board and test it with the 12V DC power source. If the fan spin up with external power source, check all the electronics wiring and fuses in RAMBo board.
On the image below you can see the hotend cooling fan being mounted. Please check the proper fan orientation - the fan pushes the air thru the extruder assembly and around the heatsink. Hot air escapes on the other side. This ensures that the heat stays at the nozzle and does not creep upwards softening the filament causing a plug.
Our award-winning customer care team is here for you.Contact Support