The case of the dirty printouts

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Brooklin

The printer:
Brother HL-1435 laser

The problem:
Smudges along the left side. Not quite a consistent pattern. Looks
like applied from a sponge. Smudging gets worse the more pages you
print. If you let the printer sit for a while and print again, the
first few pages are clean and start to get worse.

Possible suspects:
Drum cartridge. (has separate drum and toner cartridges) Replaced
cartridge, same problem.

Fuser: Looks okay as far as I can tell, but why do the first few
sheets come out clean then get dirtier?

Toner cartrige: Toner gets applied to drum. Discharge wire on drum
unit should take care of any excess toner.

Can anybody solve this case?

Thanks in Advance.
 
Brooklin said:
The printer:
Brother HL-1435 laser

The problem:
Smudges along the left side. Not quite a consistent pattern. Looks
like applied from a sponge. Smudging gets worse the more pages you
print. If you let the printer sit for a while and print again, the
first few pages are clean and start to get worse.

Possible suspects:
Drum cartridge. (has separate drum and toner cartridges) Replaced
cartridge, same problem.

Fuser: Looks okay as far as I can tell, but why do the first few
sheets come out clean then get dirtier?

Toner cartrige: Toner gets applied to drum. Discharge wire on drum
unit should take care of any excess toner.

Can anybody solve this case?

Thanks in Advance.
Click to expand...

My first thought is fuser because the first few pages are OK, this could be
caused by the fuser rollers getting warmer. In theory the fuser rollers run at
a constant temperature but in practice they often run slightly cooler for the
first few pages. This could be melting a toner deposit on one of the rollers.
The only way to be sure is to examine the rollers very carefully, this is best
done with the fuser removed, this is a bit of a pain with this printer. You can
get a reasonable view of the lower roller from the front with a torch and the
cartridge removed and a poor view of both rollers from the back with the rear
cover open but there are some output rollers in the way. If there is toner on a
roller it may be possible to remove it with warm soapy water or a proprietary
toner remover but this requires fuser removal and a great deal of care and
patience.
It is conceivable that the toner cartridge is responsible but it is unusual for
it to cause a problem of this nature since its only purpose is to evenly
distribute toner to the charged portion of the drum. However it is a
possibility.
Does the defect have a repetitive nature down the page, however subtle, and if
so how far apart are the defects? This sort of defect can take the form of a
waves and the distance between waves can be hard to measure.
Tony
 
My first thought is fuser because the first few pages are OK, this could be
caused by the fuser rollers getting warmer. In theory the fuser rollers run at
a constant temperature but in practice they often run slightly cooler for the
first few pages. This could be melting a toner deposit on one of the rollers.
The only way to be sure is to examine the rollers very carefully, this is best
done with the fuser removed, this is a bit of a pain with this printer. You can
get a reasonable view of the lower roller from the front with a torch and the
cartridge removed and a poor view of both rollers from the back with the rear
cover open but there are some output rollers in the way. If there is toner on a
roller it may be possible to remove it with warm soapy water or a proprietary
toner remover but this requires fuser removal and a great deal of care and
patience.
It is conceivable that the toner cartridge is responsible but it is unusual for
it to cause a problem of this nature since its only purpose is to evenly
distribute toner to the charged portion of the drum. However it is a
possibility.
Does the defect have a repetitive nature down the page, however subtle, and if
so how far apart are the defects? This sort of defect can take the form of a
waves and the distance between waves can be hard to measure.
Tony
Click to expand...

Tony,
Thanks for your response.

I checked the fuser (visually from the front of the printer) and the
small portion I did see seemed clean (did it a couple of times after
printing, so I should have seen a couple sections of it.)

If there is a problem with the toner cartridge, then the drum
cartridge isn't doing its job of removing all toner from the drum with
the discharge mechanism.

It's hard to determine if there was a repetitive nature to the
pattern. I was looking for a pattern to repeat itself every two to
three inches or so, but it's like the toner was applied randomly with
a sponge. Due to the nature of laser printers, there must be some sort
of repetitive pattern.

Thanks
 
Brooklin said:
Tony,
Thanks for your response.

I checked the fuser (visually from the front of the printer) and the
small portion I did see seemed clean (did it a couple of times after
printing, so I should have seen a couple sections of it.)

If there is a problem with the toner cartridge, then the drum
cartridge isn't doing its job of removing all toner from the drum with
the discharge mechanism.

It's hard to determine if there was a repetitive nature to the
pattern. I was looking for a pattern to repeat itself every two to
three inches or so, but it's like the toner was applied randomly with
a sponge. Due to the nature of laser printers, there must be some sort
of repetitive pattern.

Thanks
Click to expand...

The way that the brother cartridges work there is only a very tiny amount of
toner left on the drum, most of it is returned to the toner cartridge hopper
and a miniscule amount remains in a compartment behind the drum, this is
removed from the drum by a cleaning blade. If the drum is new and the old drum
exhibited the problem then the drum unit is not an issue and if the discharge
mechanism was not working properly you would have all sorts of issues all over
the page.
I assume you have cleaned the corona wire with the slider (sorry - just
checking :-)).

If you can borrow a toner cartridge to try that would eliminate the toner unit.
Otherwise it has to be either toner cartridge or fuser I think.
There is a slim possibility that it is the transfer roller in the printer (sits
under the drum unit) you can clean them with a dry cloth but I doubt this would
cause this problem particularly since the first few pages are OK - and that
keeps pointing to the fuser I'm afraid.
Are you able to scan a bad page and e-mail it to me or post it to
http://rapidshare.de or similar and advise the URL?
Tony
 
Brooklin said:
Tony,
Thanks for your response.

I checked the fuser (visually from the front of the printer) and the
small portion I did see seemed clean (did it a couple of times after
printing, so I should have seen a couple sections of it.)

If there is a problem with the toner cartridge, then the drum
cartridge isn't doing its job of removing all toner from the drum with
the discharge mechanism.

It's hard to determine if there was a repetitive nature to the
pattern. I was looking for a pattern to repeat itself every two to
three inches or so, but it's like the toner was applied randomly with
a sponge. Due to the nature of laser printers, there must be some sort
of repetitive pattern.

Thanks
Click to expand...

I just relised that I have overlooked the obvious.
Can you do a "half test"?
Print a multi page document, look to see when the failure starts to appear and
open the front cover of the printer while it is printing. The timing is
important, you need to stop a sheet of paper so the lower half is positioned
under the drum and the top portion is in the fuser. You may have to experiment
to get it right.
Carefully remove the paper, most of it will be unfused and will smear easily.
Examine the printout.
Is the defect present on the portion of the paper that has not reached the
fuser?
If it is then there is an imaging problem caused by Toner Cartridge, Drum unit,
transfer roller or high voltage (Unlikely as that would cause issues all over
the page).
If that part of the page is OK but the part in the fuser is bad then you have a
fuser problem.
Tony
 
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