Laser printer print defects - Black page

Problem	Possible Cause	Solution
black page	Defective toner cartridge	Install a new toner cartridge
black pages	High voltage power supply circuit is defective (not supplying the correct negative voltage)	Replace the High Voltage Power Supply PCA
black page	DC controller PCA is defective. If the DC Controller turns on the laser beam continuously, the entire surface of the Photosensitive drum is neutralized causing a completely black page.	Replace the DC Controller PCA