How to repair Light Print on Hp Color Laserjet 2600n (Laser Scanner Unit)

Laser Scanner Unit Hp Color Laserjet 2600n

Hp Color Laserjet 2600n

Hp Color Laserjet 2600n LSU Chassiess 

Printer Hp Color Laserjet 2600n LSU(Laser Scanner Unit)  the central part of laser printer that drawing data from a computer on drum then drum able to print on paper.