HP 4550 Service Manual - Page 262

No image available No image available No image available No image available CAUTION Loose toner
Loose toner is in the printer.
The toner cartridge is defective.
The paper is too smooth.
The driver setting for the paper type is wrong.
The fuser is defective. Mottled or marbled output Print a configuration page, and refer to the color blocks at the bottom of the page. Replace the toner cartridge of the color or colors that are marbled. Determine which toner color needs to be replaced by looking at the secondary colors on the selftest page. • If red and green are mottled, replace yellow. • If red and blue are mottled, replace magenta. • If green and blue are mottled, replace cyan. Random spots
The paper does not meet HP paper specifications.
You are printing on the wrong side of the paper.
The printer requires cleaning with a cleaning page.
The toner cartridge is damaged.
The imaging drum is damaged. Sharkskin (rough, mottled printing)
Use paper with lower resistivity.
Make sure the humidity and temperature are within specifications.
Do not use Automatic Duplex mode. Duplex manually or not at all. Single color missing
Remove the toner cartridge and manually check the level of toner in the toner cartridge.
Check for a defective light pipe sensor. If defective, replace the toner level sensor. Sunburn The imaging drum might have been exposed to light. Symptoms of sunburn are streaked or blurred lines across the length of the page (side-to-side on portrait, or top-to-bottom on landscape).
Print 50 to 100 pages on the imaging drum to remove the sunburn.
If sunburn symptoms are still occurring, allow the imaging drum to sit in a dark place for two to three days.
If sunburn is severe (the symptoms don't go away), replace the imaging drum. Do not expose the imaging drum to light for more than 15 seconds. The drum is light sensitive, and exposure to light can cause permanent damage. 260 Troubleshooting C7085-90921