Laserjet 4000 duplexer problems - prevents fuser working

[b33k34]

I picked up a Laserjet 4000 duplex unit that was being thrown out at
work to use on my home printer.

It creaks and squeaks in use but initially seemed ok. However, when
it's installed it seems to stop the fuser unit working properly - it's
fine for documents without much toner on the page like letters but if i
print pages with a lot of greyscale (like an excel table) the print
rubs off the page.

Has anyone else seen this problem/have any suggestions?

 

[Ed Ruf]

On 11 Jan 2007 02:58:42 -0800, in comp.periphs.printers

I picked up a Laserjet 4000 duplex unit that was being thrown out at
work to use on my home printer.

It creaks and squeaks in use but initially seemed ok. However, when
it's installed it seems to stop the fuser unit working properly - it's
fine for documents without much toner on the page like letters but if i
print pages with a lot of greyscale (like an excel table) the print
rubs off the page.

Has anyone else seen this problem/have any suggestions?

Does the addition of the duplexer change the paper path after the
fuser in a way which causes the paper to experience another short
raduis bend? Wonder if flexing the paper while still warm is an issue
or maybe just additional flexing is exacerbating an issue with a not
quite warm enough fusing process which only shows up when the page is
additionally flexed.

 

[Tony]

I picked up a Laserjet 4000 duplex unit that was being thrown out at
work to use on my home printer.

It creaks and squeaks in use but initially seemed ok. However, when
it's installed it seems to stop the fuser unit working properly - it's
fine for documents without much toner on the page like letters but if i
print pages with a lot of greyscale (like an excel table) the print
rubs off the page.

Has anyone else seen this problem/have any suggestions?

Does this happen when you print single sided? Or only double sided?
If it happens only when double sided, is the poor fusing on both sides or only
one one side of the paper?
Tony
MS MVP Printing/Imaging

 

[b33k34]

Does this happen when you print single sided? Or only double sided?
If it happens only when double sided, is the poor fusing on both sides or only
one one side of the paper?
Tony
MS MVP Printing/Imaging

Ok, it seems to have got worse and i'm now getting some rub off even
without the duplexer installed. I'm going to strip the printer down
and see if everything *looks* ok. I'm sure it won't help but it will
make me feel better.

 

[Warren Block]

Ok, it seems to have got worse and i'm now getting some rub off even
without the duplexer installed. I'm going to strip the printer down
and see if everything *looks* ok. I'm sure it won't help but it will
make me feel better.

There are two screws holding in the fuser from the back. Unscrew them
but leave them in the clips and remove the fuser by sliding it out.
Then look through the gaps at the orange fuser film on the roller. Odds
are that it's crinkled or otherwise damaged.

Some places used to sell replacement fuser film, but I never tried that.
A fuser swap with exchange would be the other option.

 

[b33k34]

Then look through the gaps at the orange fuser film on the roller. Odds
are that it's crinkled or otherwise damaged.

I've had a look and can't spot anything wrong. It does seem to be the
first of a run of pages that suffers so it's not getting hot enough (on
one centimeter wide section near the middle). If i print the page
again it's fine.

 

[Tony]

I've had a look and can't spot anything wrong. It does seem to be the
first of a run of pages that suffers so it's not getting hot enough (on
one centimeter wide section near the middle). If i print the page
again it's fine.

Did you do what Warren suggested, renove the fuser and examine bithy rollers,
is there something unusual about either of them in the centre portion?
Tony
MS MVP Printing/Imaging

 

[Tony]

Did you do what Warren suggested, renove the fuser and examine bithy rollers,
is there something unusual about either of them in the centre portion?
Tony
MS MVP Printing/Imaging

Sorry that should read -
Did you do what Warren suggested, remove the fuser and examine both rollers,
is there something unusual about either of them in the centre portion?
Just coined a new word
Tony
MS MVP Printing/Imaging

 

[b33k34]

Did you do what Warren suggested, remove the fuser and examine both rollers,
is there something unusual about either of them in the centre portion?
Just coined a new word
Tony

I've had a good look at both rollers and can't see anything unusual
about them (there are some flecks of toner in the problem area but i'd
expect that since it's not fusing properly to the pages). If i print
a larger document the latter pages are better than the first couple.

 

[Tony]

I've had a good look at both rollers and can't see anything unusual
about them (there are some flecks of toner in the problem area but i'd
expect that since it's not fusing properly to the pages). If i print
a larger document the latter pages are better than the first couple.

The bottom line is - if the printer is not fusing correctly then there is a 99%
chance that the fuser is the culprit and a 1% chance that the problem is an
electronic failure in the printer.
The 99% and 1% figures are approximate but pretty close. I guess I should also
ask what paper you are using, is it plain laser paper or are you using
something unusual?
Tony
MS MVP Printing/Imaging

 

[b33k34]

The bottom line is - if the printer is not fusing correctly then there is a 99%
chance that the fuser is the culprit

Thanks for your help on this - I've bought a new fuser unit from eBay
which will hopefully sort out the problem.

 

[b33k34]

The bottom line is - if the printer is not fusing correctly then there is a 99%
chance that the fuser is the culprit and a 1% chance that the problem is an
electronic failure in the printer.
The 99% and 1% figures are approximate but pretty close. I guess I should

It looks like I'm Mr 1%. I find it hard to believe I can be
contaminating the roller in some way but the new fuser unit is now
exibiting the same problem - a strip near the centre of the page
doesn't fuse properly.

Once a few pages have been printed it sorts itself out.

 

[Tony]

It looks like I'm Mr 1%. I find it hard to believe I can be
contaminating the roller in some way but the new fuser unit is now
exibiting the same problem - a strip near the centre of the page
doesn't fuse properly.

Once a few pages have been printed it sorts itself out.

Oh dear. I suspect the fuser is not heating up completely before the printer
permits paper movement. That is usually the fuser but can be caused by an
electronic failure in the main board I guess, I have never seen that but I
guess it is possible. There is no mechanical issue outside of the fuser itself
that can cause this so I suspect you may well be Mr 1%.
Tony
MS MVP Printing/Imaging