HP LaserJet M9040/M9050 Service Manual - Page 405

Table 7-13 Image defects (continued) Problem Cause Solution Light print, dark print, or fade The toner density setting is incorrect. Adjust the toner density setting in the control panel Print Quality menu (turn off Economode). The transfer charging roller is defective. Replace the transfer charging roller. The media fails to meet product specifications or is stored improperly. Print a few more pages to see if the problem persists. Turn the stack over in the tray, or rotate the stack 180° Use media that meets product specifications. Poor contact with the high voltage power Make sure that the drum ground spring is supply connected to the high voltage power supply. Clean the contacts if they are contaminated. If the problem persists, or if parts are damaged or deformed, replace them. Replace the high voltage power supply. The laser/scanner assembly is defective. Reseat the connectors on the laser/ scanner and the DC controller. Replace the laser/scanner if necessary. The DC controller is defective. Reseat the connectors on the DC controller and the laser/scanner assembly. Replace the DC controller if necessary. The laser shutter is defective. Check the laser shutter for correct operation while installing the print cartridge. ENWW Image-formation troubleshooting 387