TECH: Sudden faulty print with a HP LaserJet 4MV...

[BL]

Hi!

This morning when printing some pages all went fine as usual until I
hit a page with a lot of graphics on it, then the printer got a
paperjam. After that I removed the mangled paper and noticed that the
drum on the toner cartridge had toner on it (part of it). When I then
continued to print the last pages of the document, the print is not
good. It seems that the area affected (approx. half of the page (or
like 60%)) is very dim and with a lot of grey and the other part is as
perfect as always. I then took some paper and cleaned the drum of the
excessive toner and printer but same things happen again after one page
printed, the drum gets toner on the same part and the prints are bad.

I tried looking in the service manual but I can't really find an
example print there which matches my faulty prints.

Any idea on how to solve this problem? I can take a picture of both the
drum and the resulting print and upload it somewhere if that helps.

Oh yeah, one more thing is that I hear a "ticking" sound during warm-up
of the printer every time I start it, it happens until the fan(s) get
started and the printer is ready for data. This thing hasn't been any
issue for months but I thought I'd mention it, maybe it is the fuser
getting worn out?

I really hope that my toner cartridge isn't destroyed because of this
since they are pretty expensive.

Anyhow, hoping for any suggestion of how to solve this problem.

TIA!

 

[milou]

Hi!

This morning when printing some pages all went fine as usual until I
hit a page with a lot of graphics on it, then the printer got a
paperjam. After that I removed the mangled paper and noticed that the
drum on the toner cartridge had toner on it (part of it). When I then
continued to print the last pages of the document, the print is not
good. It seems that the area affected (approx. half of the page (or
like 60%)) is very dim and with a lot of grey and the other part is as
perfect as always. I then took some paper and cleaned the drum of the
excessive toner and printer but same things happen again after one page
printed, the drum gets toner on the same part and the prints are bad.

<snip>

Are you sure there isn't a bit of paper or other foreign object still
wandering somewhere inside the pinter?

 

[ato_zee]

I then took some paper and cleaned the drum of the

It could be the cartridge, it contains a scavenger blade to remove
residual toner from the drum. Symptons are grey smudges over
part of the width of the paper, and if the drum itself is damaged
repeating marks at the circumference of the drum.
Ebay often has genuine HP cartridges for older models at
low prices.
I had this problem and a new cartridge cured it, maybe there
are other possible causes, but haven't heard of any.
You are supposed to rock the cartridge gently from time to
time to redistribute the remaining toner, this often cures
blank/white tracks in printed text. Don't expose the drum to
strong light, it's photosensitive, and strong light can damage it.
Use very soft microfibre cloth with minimal pressure to clean
residual toner off the drum, it's easily damaged.
One major cause of problems is to rotate the gearing backwards.

 

[Arthur Entlich]

Hmm....

I hope when you inspected the drum that you did so under normal to dim
room lighting, and not using a bright halogen or other light source.
The drum is sensitive to bright lighting (don't use a camera flash on
it) as bright lighting can damage the light sensitivity of the drum
permanently. They sometimes improve over use/time if this has happened.

Secondly, make sure, if there is one, that the corona wire is clean.
This is a very fine stretched silver wire that usually is hidden in a
track or flap or lift lid on the cartridge. If the cartridge has access
to one, it will usually also supply some type of cleaning device for it.

You may have some paper stuck somewhere in the cartridge housing. Make
sure some of the paper that jammed didn't end up stuck somewhere within
the cartridge, or covering part of the drum or otherwise isn't rubbing
the drum partially clean. This paper scrap could be in other areas of
the printer as well blocking the laser image, or otherwise compromising
the print.

Examine the toner cartridge carefully, again under no more than dimmed
room lighting, and not for prolonged periods, looking for some jammed paper.

Art

 

[Tony]

If you can post an image of the defect it may help.
The printer is A3 so please post the whole page so that the orientation is
obvious since this is critical to good diagnosis.
Tony

 

[BL]

Tony (and others),

Here is a picture of an A3 page printed
(http://img178.imageshack.us/img178/4906/4mvfaultygm0.jpg). I don't
think I managed to resize the page to expand to A3 but maybe it doesn't
matter any longer as the problem has developed into to cover the whole
pages now (after only printing 4-5 more pages). Also, the picture
quality (light) isn't exactly optimal but one can clearly see that the
paper background is grey and that old prints still occur in the grey
area.

I also looked at this link;
http://www.fixyourownprinter.com/forums/laser/12433 where they talk
about "wipers" in the toner cartridge which has gone bad (and may be
replaced (anyone got a cheap source?), maybe that is my problem? It's
just strange (I think) that it happened after one page got jammed
(going from good standard prints to bad ones in a flip of a coin sort
of).

I have a brand new toner cartridge (HP original) which I naturally can
install, it's just that I want to know if the problem lies elsewhere so
I can rectify that problem first and to use what's left of my current
toner (which is quite a lot I think) as well as I do not want to
destroy a new and perfect cartridge if all that's needed is to print
one single page (they aren't that cheap after all).

Anyhow, if someone has any good idea I'd be more than greatful!

TIA!



Tony skrev:

 

[Tony]

This looks like a classic wiper blade failure. The paper jam is likely to be
coincidence.
See the ghosting (the repeated image lighter than the original but a bit
further down the page) that is caused because the original image was not wiped
from the drum. This lack of correct wiping also produces the grey background.
I do not know where you can buy wiper blades for this in your country, if you
can find a Static Control Corporation dealer they may sell you one.
There are some tricks to installing the blade.
1. You need to split the cartridge in half (if you decide to go ahead I will
see if I can find instructions for this cartridge).
2. You need to keep the drum away from the light while you do the job.
3. You need to wear latex or similar "medical" gloves to keep any skin oils
away from all components.
4. The blade needs a special dry powder lubricant to be applied to the edge
that is in contact with the drum, not too much however. This lubricant is also
made by Static Control but you need much less than a gram and it is normally
sold in 500 gram or similar amounts but if you can find a source for the blade
they might put a small amount of lubricant with it (half a teaspoon is plenty).
Before you consider this are you sure the cartridge has plenty of toner left?
You can check this by weighing it and your new cartridge and let me know what
the difference in weight is, somewhere I think I have the toner weight listed.
Tony

 

[BL]

Tony!

If you're pretty sure this is the problem I can of course install the
new HP original toner cartridge I have since the method you describe
(to replace the wiper or fix it)sounds very difficult without even
thinking about the parts etc.

Before I do this however, I just want to make sure that spilled toner
elsewhere in the printer can't damage the new toner cartridge. Maybe I
should check if paper is left somewhere as well or clean some rollers
or something?

By the way, did you see my initial post in this thread about the
"clicking" sound, do you know if that is anything to worry about?


TIA!.



Tony skrev:

 

[Tony]

I have never seen a printer damage a toner cartridge. I have seen labels get
stuck on a toner cartridge drum.
If you have any paper in the printer then it is unlikely that you could feed
paper at all.
The paper path in this printer is very short and all of it is in or near the
front door, tou can clean any toner you see with a soft dry cloth but generally
toner spills do not contaminate the printed page unless they are very bad, and
even then they slowly get removed by the paper. Spilled toner can in extreme
cases damage a fuser roller, I saw no sign of any fuser damage on your scan.
I think you can safely try the new toner. You may well find the clicking sound
goes away with a new toner.
Good luck
Tony

 

[BL]

Tony!

I've replaced the toner cartridge... it works!

I got some "new effects" though, maybe it will disappear after a while,
I don't know.

After reading the service manual I think I have a problem with the
"fuser inlet guide" since I get a "leading edge halo" effect, I get a
small grey area (almost like a shadow) around text and graphics which
are on the first part of the page (about 20% of the page is affected).

The ticking sound is still there (and the new cartridge has it's own
new "sound effects" ) but as long as that isn't indicating any real
fault/danger it's no problem with me.

Thank you so much for your help!



Tony skrev: