The Samsung CLX-3185 printer uses a toner chip to monitor the toner level in the cartridge. When the toner level falls below a certain threshold, the printer will display a message indicating that the toner is low or empty. While this is a useful feature to alert users when the toner needs to be replaced, it can also be problematic if the toner chip is faulty or if the user wants to use a refilled or compatible toner cartridge.