Uneven Density - Samsung SCX-4720F Service Manual

Troubleshooting

7.3.7 Uneven Density

• Description Print density is uneven between left and right.
7.3.8 Background
• Description Light dark background appears in whole area of the printing.
Digital Printer
Digital Printer
Digital Printer
Digital Printer
Digital Printer
Service Manual
7-12
Check and Cause
1. The pressure force on the left and right
springs of the transfer roller is not even,
the springs are damaged, the transfer
roller is improperly installed, or the trans-
fer roller bushing or holders are damaged.
2. The life of the Toner cartridge has
expired.
3. The toner level is not even on the toner
cartridge roller due to the damaged blade
or low toner.
Check and Cause
1. Printing large quantities of low coverage
(2%) pages or the printer has not been
used for a long time.
2. Is a recycled toner cartridge be
used?
3. Has the life span of the toner
cartridge ended?
4. Is the movement(Up and Down) of
the transfer roller smooth?
5. Is the HVPS normal?
Solution
1. Replace both the left and right bush and
spring assemblies.
2. Replace the toner cartridge and try to print out
3. Gently shake the toner cartridge and try
printing again. If the problem persists
replace the toner cartridge.
Solution
1. The toner cartridge is basically designed to
print 3,000 sheets with 5% image. If it
prints more than 3,600 sheets with 2%
coverage, a background can occur.
2. The A/S is not guaranteed if using a recy-
cled toner cartridge.
Note try shaking the toner cartridge gently
from side to side. If the problem persists
replace the toner cartridge.
3. Replace the toner cartridge when its life is
expired.
4. Clean the transfer roller bushes.
5. Clean the high voltage charge terminals.
If this does not resolve the problem replace
the HVPS.
Samsung Electronics