Troubleshooting
Service Manual
7-9
Samsung Electronics
7.3 Paper Feed Problems – Causes and Solutions
7.3.1 Wrong Print Position
• Description
Printing begins when the paper is in the wrong position.
Digital Printer
Digital Printer
Digital Printer
Digital Printer
Digital Printer
Check and Cause
Solution
A defective feed sensor actuator can cause
incorrect timing.
Replace the defective actuator
7.3.2 Vertical White Line
• Description
White vertical voids in the image.
Digital Printer
Digital Printer
Digital Printer
Digital Printer
Digital Printer
Check and Cause
Solution
1. 1. Contamination of the window or
internal lenses of LSU mirror.
2. Foreign object inside the toner cartridge
or low toner.
3. Foreign object, contamination or burr on
the edge of the toner cartridge window.
4. If the fuser is defective, voids occur
periodically at the top of a black image.
5. Contamination of the OPC drum.
6. Depression or deformation of the surface
of the transfer roller
1. Clean the LSU window with recommended
cleaner (IPA) Clean the window with a
clean cotton swab. If dirt is inside the LSU
– replace LSU.
2. Replace the toner cartridge.
3. Clean the exposure window.
4. Open the front cover and check the ribs
that correspond to the position of the
voids. Remove if found.
5. If the problems are not solved, replace
the toner cartridge.
6. Replace the transfer roller.
Summary of Contents for SCX-4720F
Page 10: ...Service Manual Reference Information 2 4 Samsung Electronics 2 3 2 A4 2 Pattern...
Page 11: ...Reference Information Samsung Electronics Service Manual 2 5 2 3 3 A4 IDC 5 Patten...
Page 14: ...Service Manual Reference Information 2 8 Samsung Electronics MEMO...
Page 24: ...Service Manual Specifications 3 10 Samsung Electronics MEMO...
Page 27: ...Summary of Product Service Manual 4 3 Samsung Electronics 4 1 3 Control Panel SCX 4720F...
Page 28: ...Service Manual Summary of Product 4 4 Samsung Electronics...
Page 51: ...Summary of Product Service Manual 4 27 Samsung Electronics MEMO...
Page 163: ...Service Manual Exploded View Parts List 8 28 Samsung Electronics MEMO...