White spots in firefly patterns, or black comet streaking patterns appear.
Cause:
Toner clumping can cause white firefly patterns with white spots in the center of kernels. These clumps can also cause degradation in image areas which leads to black, streaked comet patterns. These problems may occur when:
- The machine has remained idle for a long period, especially where ambient temperature was high.
- The machine was moved or shipped and was subjected to severe shock or vibration.
- Toner not used for a long period, especially where ambient temperature was high.
Solution:
- Print a test sheet at 100% coverage. Do you see firefly or comet patterns?
Yes
Go to the next step.
No
Finished!
- Print 350 A3 sheets at 100% coverage. Do you see firefly or comet patterns?
Yes
Go to the next step.
No
Finished!
- Replace toner, and then print 350 A3 sheets at 100% coverage. Do you see firefly or comet patterns?
Yes
Go to the next step.
No
Finished!
- Replace the toner sub hopper, and then print 350 A3 sheets at 100% coverage. Do you see firefly or comet patterns?
Yes
Go to the next step.
No
Finished!
- Replace the development unit and the developer, and then print some test prints at 100% coverage. Do you see firefly or comet patterns?
Yes
The problem requires further analysis. Consult the product specialist.
No
Finished!