HP Color LaserJet MFP E78330

Blurred image

 

Step	Cause	Action
1	High humidity and/or the quality of the paper.	Use new, higher quality paper.
2	T2 transfer voltage is low.	Turn up the T2 transfer voltage.
3	Connection between HVPS and THV is incorrect.	Check if the connection between T2 high voltage terminal and HVPS THV terminal is correct. Check if the connection between the HVPS and ITB is correct.
4	HVPS operates abnormally.	Replace the HVPS.

Incorrect color registration

 

Step	Cause	Action
1	CPR execution is needed.	Execute CPR manually.
2	CPR sensor is contaminated.	Clean the CPR sensor.
3	Environmental circumstances - such as temperature or humidity - have changed.	To recognize the environment change, execute CPR after a enough time has passed for the printer to become acclimated.
4	Check if the skew occurs at the trays or feeding rollers.	Adjust the skew manually.
5	Belt surface is contaminated.	Remove the ITB. If the surface of the belt is contaminated, clean with a soft cloth.

Uneven pitch and jitter image

 

Step	Cause	Action
1	Under 3 mm periodic jitters or horizontal bands have occurred.	Check for foreign substance in the drive gears. Grease the drive gears. - Developer unit gears - Drum unit gears - Main drive unit gears If the problem persists, replace the abnormal units. - Developer unit - Drum unit - Main drive unit
2	Under 1 mm periodic jitters or horizontal bands have occurred.	Check if the laser scanner assembly is installed correctly. If not, remove and tighten the screws. If the problem persists, replace the laser scanner assembly