how to stop black dots printed on document? 1

[bloomlight]

We have HP laserjet 4200 printer. User noticed that some balck dots appear on printed documents. How to fix it? Any ideas? Thanks.

 

[Sweg]

Is this a repetitive defect? (image defects that appear at regular intervals on the page)

If it is you could check this ruler:

37.7 mm (1.5 inches) primary charging roller
54.0 mm (2.125 inches) developer roller (see note)*
62.8 mm (2.5 inches) developer roller (see note)*
94.0 mm (3.75 inches) fuser (HP LaserJet 4300)
94.2 mm (3.75 inches) photosensitive drum

If there are only black dots like you said on the paper you probably have a bad toner cartridge. Change the cartridge and the problem should be solved.

 

[gbaughma]

Sweg: Great piece of info. Gave you a star.



Just my 2¢

"In order to start solving a problem, one must first identify its owner." --Me
--Greg

http://parallel.tzo.com

 

[bloomlight]

I took Sweg's suggestion and changed toner cartridge in July. The dots disappeared.

Just recently, the pritner prints about 1" wide of black area cross the paper from top to buttom. It only appears on the left side. I tried cleaning paper thru the printer and cleaning the fuser followed instructions. The printing quality is getting worse and worse ....... What should I do now? Thanks.

 

[hpwizzard]

You might want to start off by doing a half test to determine what is the cause by stopping a sample printjob when the paper is passing the toner cartridge by lifting the top lid. This might be a little tricky but in the end you will succeed stopping at the right time.
Now...
1) When you have stopped the paper while it's passing the toner, take out the toner and inspect the drum.
2) If you recon the banding is present on the drum you might have a bad toner, dirty transfer roller or the laser mirror could have been contaminated.
3) If the edges of the banding appear to look sharp without any blur on the edges, you can probably blame the laser scanner for it.
4) If the banding is there and appears a little blurred on the edges exchange the cartridge first. If you still get defects after a cartridge exchange the transfer roller is probably dirty.
5) If the banding is not present at this stage a worn or dirty fuser roller is to blame.

Note :
If you notice the fuser is worn, check up on the page count of the printer. If it's close to a maintenance interval or has printed more than 150.000 pages you might be better off exchanging a whole maintenance kit including both fuser, transfer & pickup rollers. Good luck !