Samsung SCX-4720FN

ROUBLESHOOTING

9.20

Toner specs

• The paper may not meet specifications; for example, the

paper is too moist or too rough. See “Paper Specifications”

on page D.6.

• The transfer roller may be dirty. Clean the inside of your

machine. See “Cleaning the Inside” on page 8.3.

• The paper path may need cleaning. See “Cleaning the

Drum” on page 8.10.

Dropouts

If faded areas, generally rounded, occur randomly on the

page:

• A single sheet of paper may be defective. Try reprinting the

job.

• The moisture content of the paper is uneven or the paper

has moist spots on its surface. Try a different brand of

paper. See “Paper Specifications” on page D.6.

• The paper lot is bad. The manufacturing processes can

cause some areas to reject toner. Try a different kind or

brand of paper.

• The toner cartridge may be defective. See “

Vertical

repetitive defects

” on page 9.21.

• If these steps do not correct the problem, contact a service

representative.

Vertical lines

If black vertical streaks appear on the page:

• The drum inside the toner cartridge has probably been

scratched. Remove the toner cartridge and install a new

one. See “Replacing the Toner Cartridge” on page 8.8.

If white vertical streaks appear on the page:

• The surface of the LSU part inside the machine may be

dirty. Clean the LSU (see page 8.4).

Gray background

If the amount of background shading becomes

unacceptable:

• Change to a lighter weight paper. See “Paper

Specifications” on page D.6.

• Check the machine’s environment: very dry (low humidity)

or high humidity (higher than 80% RH) conditions can

increase the amount of background shading.

• Remove the old toner cartridge and install a new one. See

“Replacing the Toner Cartridge” on page 8.8.

Condition Suggested solutions

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