If you know about 3d printers could you me fix mine?

i have a monoprice, mini version 2. i've tried cleaning it (3 times) making sure the filament is all the way in (the plastic), i've tried calling the people at monoprice and looking it up.

no matter what i do the extruder won't let out any filament when i click print and or extrude.

does anyone know what the problem is and can you explain what i can do to fix it? ?