Samsung ML-3750ND User Manual page 155

Storing the toner cartridge
Samsung's printer warranty does not cover damage to the
machine caused by the use of a refilled, remanufactured, or
non-Samsung brand toner cartridges.
3
Estimated cartridge life
Estimated cartridge life (the life of the toner cartridge yield) depends
on the amount of toner that print jobs require. The actual print yield
may vary depending on the print density of the pages you print on,
operating environment, printing interval, media type and/or media
size. For example, if you print a lot of graphics, the consumption of
the toner is higher and you may need to change the cartridge more
often.
5. Maintenance 60