Service manual

Troubleshooting
Samsung Electronics 4-15
It is needed in the development progress. Service person doesn't need to use it.
4-6 Troubleshooting
4-6-1 Scanner
4-6-1-1 COPY
PROBLEM ITEMS TO BE CHECKED. HOW TO SOLVE
White copy • Check the Scan-Cover open. • Room light can transit a thin original.
• Check shading profile. • Remake shading profile in the tech mode.
• Check white/black reference voltage in
Main PBA.
• Replace U16 if it is defective.
- U16-97 = 2.5V - U16-98 = 3.3V
- U16-99 = 1.5V
• Check turning the CCD Lamp on when
operating.
• If the CCD is defective, replace it.
- CN3-19 is 5.8V when white original copy-
ing for R, B and 3.5V for G.
Black copy • Check the CCD problem in Main PBA. • Check the CCD harness contact.
• Check shading profile. • Remake shading profile in the tech mode.
• Check the CCD problem in Main PBA. • If the CCD is defective, replace it.
- Cn3-19 is 7.3V when idle for R, B, and 5V
for G.
Defective image quality • Check shading profile. • Remake shading profile in the tech mode.
• Check the gap between original and scan-
ner glass.
• The gap above 0.5mm can cause a
blurred image.
• Check printing quality. • See “Print” troubleshooting.
Abnormal noise • Check the Scanner Motor and any
mechanical disturbance.
• Check the right position of the Scanner
Motor, and check the any mechanical dis-
turbance in the CCD carriaging part.
• Check the Motor Driver in Driver PBA. • If any driver is defective, replace it.
- U55-1 or U55-15 = 0V to 24V swing signal
when operating.