HP Pro 4300 C9H70UT C9H70UT#ABA manual Repeating defects and repeating images, Distorted images

Table 62. Repeating defects and repeating images

Possible cause	Recommended action(s)
The print cartridge or fuser is damaged.	1. Inspect the drum for scratches or other damage. Replace
The circumference of the	the print cartridge for defects that repeat at 37.7 mm
photoconductive drum inside of the print	(1.5 inches), 62.8 mm (2.5 inches), 54.0 mm (2.1 inches),
cartridge is 94.2 mm (3.7 inches). If the	and/or 94.2 mm (3.7 inches).
defect repeats at this interval, the defect	2. Process a printer cleaning page. See “Running the cleaning
is associated with the drum.	page manually” on page 56.
Repetitive defects caused by the	3. If the problem persists, and the defect repeats at the
	75.0 mm (2.95 inches) or 94.0 mm (about 3.7 inches)
LJ 4300 fuser roller repeat at 94.0 mm	replace the fuser (see “Fuser” on page 162). For more
(about 3.7 inches) Because the LJ 4300	information about repetitive defects, see “Repetitive defects
fuser roller is just 2 mm (.07 inch)	troubleshooting” on page 325.
smaller than the photoconductive drum
it can be difficult to distinguish defects
caused by the photoconductive drum
from those caused by the LJ 4300 fuser
roller.
Dirty rollers. A dirty roller in the paper	● Examine and clean (or replace) the rollers in the paper path.
path can cause a repetitive defect.
Media does not meet specifications. The	● Try a different paper.
surface might be too coarse, which can
cause repeating marks.
Pre-printed form paper is used.	● Some pre-printed forms (for example, letterheads) use an ink
	that cannot stand up to the high temperatures in the fuser.
	Check the media for type and quality. Replace the media, and
	advise the customer to use the HP recommended media and to
	store it correctly. See “Paper specifications” on page 9.

For more information about troubleshooting repeating defects, see “Repetitive defects troubleshooting” on page 325.

Table 63. Distorted images

Possible cause	Recommended action(s)
The media does not meet specifications	1. Turn over the stack of media in the tray. Also try rotating the
or is not stored properly.	media 180 degrees.
	2. Check the media for type and quality. Replace the media,
	and advise the customer to use the HP recommended
	media and to store it correctly. See “Paper specifications” on
	page 9.
The printers operating environment	● Make sure the printer is installed in the proper environment.
does not meet specifications.	See “Environmental specifications” on page 7.
Poor connection of the cables to the	● Reseat the cables that are connected to the laser/scanner
laser/scanner assembly.	assembly.
Poor connection of the cables to the	● Reseat the cables that are connected to the
DC controller PCA.	DC controller PCA.
The laser/scanner assembly is	● Replace the laser/scanner. See “Laser/scanner assembly” on
defective.	page 173.
Gears are worn, causing slippage or	● Inspect the gears that drive the print cartridge and fuser.
jumping.	Replace the main drive assembly. See “Main drive assembly” on
	page 186.
The print cartridge motor is defective.	● Replace the print cartridge motor (HP LaserJet 4300 only).
HP LaserJet 4300 only	See “Print-cartridge motor (HP LaserJet 4300 series printer
	only)” on page 175.
The DC controller PCA is defective.	● Replace the DC controller PCA. See “DC controller PCA” on
	page 181.

318 Troubleshooting Q2431-90912