If you are having problems loading filament into one of the extruders, perform the following steps:
1. Using the LCD panel, navigate to Utilities > Filament Options > Unload. This option heats the extruders.
2. Make a fresh cut at the end of the filament. It is important that the filament have no bends in it. If there are bends, cut off the bent section of filament.
3. Insert the filament into the hole at the top of the extruder. Keep pushing it in until you start to see plastic come out of the nozzle.
You might have to apply some pressure.
4. When the filament is successfully loaded, set the extruder lever arm to the closed position.

If filament doesn’t emerge from the nozzle, try the following solutions:
• Remove the filament from the top of the extruder and check for a bend at the end of the filament.
If the filament is bent, it is possible that the filament is slipping under the extruder bearing instead of entering the hot end.

• Remove the extruder fan and assembly using the instructions in the section Disassembling an Extruder.
This will allow you to watch the filament travel through the extruder and determine where the filament is getting stuck.
This will also allow you to see if a piece of filament is stuck inside the extruder.