Samsung ML-2251NP - Manual (Page 111)

M AINTAINING Y OUR PRINTER
5.6
2 Open the front cover. Pull the toner cartridge and remove it
from the printer.
3 With a dry, lint-free cloth, wipe away any dust and spilled
toner from the toner cartridge area and the toner cartridge
cavity.
N OTE : To prevent damage to the toner cartridge, do not expose it
to light for more than a few minutes. Cover it with a piece of
paper, if necessary and keep it in a flat and clean place. Also, do
not touch the black transfer roller inside the printer.
4 Locate the long strip of glass (LSU) inside the top of the
cartridge compartment, and gently swab the glass to see if
dirt turns the white cotton black.