HP Pro 4300 C9H70UT C9H70UT#ABA manual White lines opposite the paper path

Table 67. White lines

Possible cause Recommended action(s)

	White lines in the paper path
	Toner supply is low or the print cartridge	1. Shake the print cartridge gently to redistribute the toner.
	is defective.	2.	Replace the cartridge.
	Dirt in the laser path.	● Clean the laser path. Remove the laser/scanner assembly (see
		“Laser/scanner assembly” on page 173) and check for dirt or
		other obstructions in the beam path.
	The fuser is defective.	● Replace the fuser. See “Fuser” on page 162.
	Dirty mirror in the laser/scanner.	● Replace the laser/scanner assembly. See “Laser/scanner
		assembly” on page 173
	White lines opposite the paper path
	The print drum is damaged.	● Replace the print cartridge.
	The fuser roller is damaged.	● Process a printer cleaning page. See “Running the cleaning
		page manually” on page 56.
		● If the problem persists, replace the fuser. See“Fuser” on
		page 162.
	Unstable laser beam or beam circuitry.	● Replace the following in order:
		1.	Laser/scanner assembly. See “Laser/scanner assembly” on
			page 173.
		2. DC controller PCA. See “DC controller PCA” on page 181.
		3. Cables between the DC controller PCA and the
			laser/scanner assembly.
		4. Formatter assembly. See “Formatter assembly” on
			page 161.
Table 68. Smudged lines (either direction)
	Possible cause	Recommended action(s)
	Paper path contamination or damage.	1. Perform the half self-test functional check. See “Half self-test
			functional check” on page 310. If the defect developed on
			the drum, replace the print cartridge.
		2. Process a printer cleaning page. See “Running the cleaning
			page manually” on page 56. If the problem persists, replace
			the fuser. See “Fuser” on page 162.
		3. Check the tray 1 feed roller and the other tray’s rollers for
			contamination. Clean or replace as necessary.
		4. Check for other sources of contamination or damage in the
			paper path and clean or replace as necessary.
	The print cartridge has passed its life	● The print cartridge has an expected life of 12,000 pages for the
	expectancy.	HP LaserJet 4200 printer and 18,000 pages for the
		HP LaserJet 4300 printer. Replace the print cartridge.

This type of defect might also be a repetitive defect, See “Repetitive defects troubleshooting” on page 325.

320 Troubleshooting Q2431-90912