laser printer problem - streaks across the page

[mad.scientist.jr]

My laser printers (old reliable HP LaserJet 4 and 4L) both have
developed this problem where any print outs have streaks on the paper
and you can even rub the paper and the print will come off on your
fingers as a fine black dust. Here is an example:

http://www.geocities.com/usenet_daughter/laser_printer_mess.jpg

The toner isn't even that old. I tried blowing compressed air into the
printer to clean out dust but I am still seeing the problem.

Is this something that can be corrected?

Any help would be appreciated.

Thanks...

 

[Tony]

My laser printers (old reliable HP LaserJet 4 and 4L) both have
developed this problem where any print outs have streaks on the paper
and you can even rub the paper and the print will come off on your
fingers as a fine black dust. Here is an example:

http://www.geocities.com/usenet_daughter/laser_printer_mess.jpg

The toner isn't even that old. I tried blowing compressed air into the
printer to clean out dust but I am still seeing the problem.

Is this something that can be corrected?

Any help would be appreciated.

Thanks...

The image looks like either toner cartrdige or fuser. The fact that the toner
rubs off definitely indicates fuser.
Does the toner rub off from both printers?
It is difficult to do from the image you posted so can you measure the precise
vertical distance between the top two identical marks, I see some repeating
marks in the image on the centre vertical band. Which printer produced this
image?

Tony
MS MVP Printing/Imaging

 

[mad.scientist.jr]

Thanks for your reply. Yes, the toner rubs off the paper from both
printers. Here are 300 dpi scans of printouts from both printers:

HP Laserjet 4
http://www.geocities.com/usenet_daughter/laserjet_4_problem_1.jpg
http://www.geocities.com/usenet_daughter/laserjet_4_problem_1_back.jpg
http://www.geocities.com/usenet_daughter/laserjet_4_problem_2.jpg

HP Laserjet 4L
http://www.geocities.com/usenet_daughter/laserjet_4l_problem_2.jpg
http://www.geocities.com/usenet_daughter/laserjet_4l_problem_1.jpg

from wikipedia:
fuser, the part of a laser printer that melts the toner onto the
medium. It consists of a hot roller and a back-up roller. After toner
is transferred to the paper, the fuser applies heat and pressure to
ensure that the toner stays on the paper permanently. This is why
paper is warm when it comes out of a laser printer.

 

[mad.scientist.jr]

Actually the toner only rubs off from the Laserjet 4L's printouts (and
my memory it seems) - I rubbed and rubbed the Laserjet 4 printouts but
no genie appeared. The toner doesn't rub off from the laserjet 4
printouts. Sorry about the confusion.

 

[Tony]

The Laserjet 4L has a fuser problem. They are not too hard to replace but the
question is whether it is worth it, maybe a second hand Laserjet 4 or 4+ would
be a better resolution.
The Laserjet 4 appears to have a cartridge problem. Do a half test as follows -
Print one sheet from the fold down tray, just as the trailing edge of the paper
goes into the printer open the toner door to stop the printer. Remove the toner
cartridge, are the marks on the paper that you can see in the printer? If they
are there the cartridge needs replacing.
Tony

 

[mad.scientist.jr]

For the fuser problem, would blowing out the fuser as described here

http://wiki.freegeek.org/index.php/Repair_of_Laserjet_Printers

help?

I will try the test you describe below.

Thanks for your help...

 

[Tony]

You can try cleaning as described but be very careful, the fuser roller is very
easy to damage and nowhere near as robust as it looks. Personally I doubt that
cleaning it will resolve ghosting but who knows? There is no way that ghosting
will be caused by dust.
Good luck
Tony

 

[smlunatick]

For the fuser problem, would blowing out the fuser as described here

http://wiki.freegeek.org/index.php/Repair_of_Laserjet_Printers

help?

I will try the test you describe below.

Thanks for your help...




- Show quoted text -

Several fusers have a film which seems to be using the "fusing" of the
toner to the paper. If this film is damage, you will need to replace
the complete fuser assembly. Fuser assemblies can be more expensive
that a reconditions / used printer.

 

[Arthur Entlich]

The need for toner coating on a fuser doesn't seem correct to me, but
I'm willing to learn. Photocopiers and laser printers use a thin layer
of toner on the optical drum to help in the release of the paper as it
goes through, and to lubricate the wiper blade so it doesn't scratch the
drum surface. However, the fusers usually have a thin Teflon coating
which is designed to keep the toner fused onto the paper, and not to
transfer or stick to the fuser surface. In fact, most fusers have a
replaceable felt wiper to remove any excess toner that might remain behind.

Some fusers do require "fuser oil" which is usually a silicon oil that
helps to keep the surface of the fuser even more non-stick (this is more
common with color laser printers where the toner has more plastic
component and tends to be denser coverage and may require higher fusing
heat). These oils can also help to produce a more glossy output.

Toner powder not fusing properly to the paper usually is caused either
by a fuser which is not heating to proper temperature (could be the heat
sensor, or other electronics or power supply issues), improper paper
surface (paper which simply doesn't allow the toner to bond due to waxes
or characteristics), too thick a paper for the printer, or improper
toner type. Toners are not all the same by am means. Not only do the
technologies and chemistries of the toners vary, but fusing temperature
can also be quite different.

As to fusers requiring a coating of toner, can the original poster
provide an references If so, please post them so I can become better
informed.

Thanks,

Art

smlunatick wrote:

 

[Tony]

Several fusers have a film which seems to be using the "fusing" of the
toner to the paper. If this film is damage, you will need to replace
the complete fuser assembly. Fuser assemblies can be more expensive
that a reconditions / used printer.

Some fusers use a sleeve (film?) around the heating element, some have a solid
heated roller (sometimes 2). Some sleeves are easy to replace and some are near
impossible. Sleeves are usually lubricated on the inside, these fusers do not
need any external lubrication.
Tony
MS MVP Printing/Imaging