Samsung ML-6050 Service Manual page 34

Troubleshooting
Error code 1-020
Fault
White vertical stripes
Description
White vertical voids in the image.
Check
1. LSU
2. Developer cartridge
3. Fuser
Cause
1. Foreign matter stuck onto the window of internal lens of LSU mirror
2. Foreign matter or toner particles between the developer roller and blade
3. If the fuser is defective, voids occur periodically at the top of a black image.
Solution
1. Clean the LSU window with a recommended cleaner, or replace the LSU window.
2. Replace the developer cartridge if defective.
3. Open rear cover and check ribs in the fuser for contamination. Clean if necessary.
Remark
Use LSU cleaner dated after January 1997.
Others
If white streaks occurs fewer than 5 or 6 times, it can be considered as normal.
5-2
Model ML-xxxx
Samsung Electronics