Samsung SL-M4580FX Service Manual page 233

10) Stains on back of page
Description : The back of the page is stained.
Probable Cause
The transfer roller is contaminated or worn out.
The pressure roller or heat roller in fuser unit defective.
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Solution
Replace the transfer roller.
1) Turn the machine off.
2) Remove and replace the fuser unit.
3) Turn the machine on.
WARNING
Do not touch the fuser unit while it is hot.
4. Troubleshooting
4-130