Samsung CLX-318X - Manual (Page 137)

Supplies and accessories_ 5
6. Insert the new container into position and then push it to make sure that
it is firmly seated in place.
7. Close the front door firmly.
If the front door is not completely closed, the machine will not
operate. Please, make sure all toner cartridges are installed
properly. If any toner cartridge is installed improperly, the front
door do not close.
8. Turn the machine on.