Samsung ML-2151N-XBH - Manual (Page 127)

M AINTAINING Y OUR PRINTER 6.10
Consumables and Replacement
Parts
From time to time, you will need to replace the toner cartridge,
roller, and fuser unit to maintain top performance and avoid
print quality problems and paper feed problems resulting from
worn parts.
The following items should be replaced after you have printed a
specified number of pages. See the table below.
To purchase the consumables and replacement parts, contact
your Samsung dealer or the retailer where you bought your
machine. We strongly recommend that items be installed by a
trained service professional, except for the toner cartridge.
Items Yield (Average)
Paper feeding roller 100,000
Transfer roller 100,000
Pick-up roller 100,000
Fuser unit 100,000