6. Troubleshooting
Test pattern check
Low image density on the output
The main scan registration is shifted,
but only at the central area of the
image on the output.
The main scan registrations of M, C,
Y, K are shifted.
The sub scan registrations of M, C, Y,
K are shifted.
710
Possible cause/Countermeasure
• Low pattern density
Do the forced process control (SP3-011-001) or supply
some toner (SP3-030-xxx).
• Defective ID sensor at center
• Deformed center area on the image transfer belt
• Defective BICU
1. Replace the ID sensor.
2. Replace the image transfer belt.
3. Replace the BICU.
• Defective laser optics housing unit
• Defective ID sensor
• Defective BICU
• Incorrect SP value
1. Perform the color skew adjustment (
2. Replace the laser optics housing unit.
3. Replace the ID sensor.
4. Replace the BICU.
5. Adjust the value with SP2-182-004 to -021.
• Defective image transfer belt
• Defective drive units
• Defective ID sensor
• Defective BICU
• Incorrect SP value
1. Replace the image transfer belt.
2. Replace the ID sensor.
3. Replace the drum motor.
4. Replace the BICU.
5. Adjust the value with SP2-182-022 to -039.
p.159).