Canon i850 ink tank cross contamination

[Michael Brown]

I have a Canon i850 color printer - my yellow tank is being contaminated
from the cyan (I suspect - since anything yellow now prints green). The
tanks are installed in the correct slots (never mixed up), and snapped
into place. There are no error lights blinking on the printer or in the
user interface.

History:

After the original canon brand tanks ran out, I replaced them with G&G
brand from abcink.com - those worked just fine. When those ran out I
replaced with another set of G&G brand. I don't remember how long
after, but one day things didn't print correctly. That time it appeared
everything printed in various shades of purple. I first blamed my kids
for messing with it, but nobody did. I removed all four tanks, and then
print head - washed it warm water until it ran clean. I even removed
two small screws and seperated what looks a ceramic square (contains the
print nozzles). There was small multi-hole rubber gasket that sealed
that piece to the plastic that held the ink tanks - that appears in good
shape. Everything was allowed to dry. I re-assembled the head, put in
four new G&G tanks and after a few deep clean runs and an allignment it
worked good as new. Couple weeks later - my yellow tank was
contaminated with a dark color - anything yellow printed green. I
cleaned everything up again, four new tanks - worked great - a couple
weeks later again - the yellow tank was contaminated again - prints
green.

Is the generic ink to blame? The first four tanks for G&G worked just
fine - no problems

Bad print head? I can order one for 47.07 + $5 shipping from Canon

What about where the print head sits when its off? Could something be
leeching up from the waste area? (or whatever the place is called that
the printer shoots the ink during a cleaning).

 

[MCheu]

What about where the print head sits when its off? Could something be
leeching up from the waste area? (or whatever the place is called that
the printer shoots the ink during a cleaning).

You know, I've often wondered about that. With other printers, when
it does a cleaning cycle, it just hoses down a piece of paper with
ink. The canons, however, run through this long winded meditation
cycle with every power up that's supposed to be some sort of cleaning
cycle. What the heck does it do with the ink?

 

[PC Medic]

I have a Canon i850 color printer - my yellow tank is being contaminated
from the cyan (I suspect - since anything yellow now prints green). The
tanks are installed in the correct slots (never mixed up), and snapped
into place. There are no error lights blinking on the printer or in the
user interface.

History:

After the original canon brand tanks ran out, I replaced them with G&G
brand from abcink.com - those worked just fine. When those ran out I
replaced with another set of G&G brand. I don't remember how long
after, but one day things didn't print correctly. That time it appeared
everything printed in various shades of purple. I first blamed my kids
for messing with it, but nobody did. I removed all four tanks, and then
print head - washed it warm water until it ran clean. I even removed
two small screws and seperated what looks a ceramic square (contains the
print nozzles). There was small multi-hole rubber gasket that sealed
that piece to the plastic that held the ink tanks - that appears in good
shape. Everything was allowed to dry. I re-assembled the head, put in
four new G&G tanks and after a few deep clean runs and an allignment it
worked good as new. Couple weeks later - my yellow tank was
contaminated with a dark color - anything yellow printed green. I
cleaned everything up again, four new tanks - worked great - a couple
weeks later again - the yellow tank was contaminated again - prints
green.

Is the generic ink to blame? The first four tanks for G&G worked just
fine - no problems

Bad print head? I can order one for 47.07 + $5 shipping from Canon

What about where the print head sits when its off? Could something be
leeching up from the waste area? (or whatever the place is called that
the printer shoots the ink during a cleaning).

While I am not one to jump right out and say it is the ink, it is certainly
possible in your case. Could be causing the seals to prematurely dry and
shrink allowing the cross-contamination. Why not try OEM's to at least
confirm the ink theory?

While it is 'possible' that the head is not parking over the purge unit
properly, this would be a long as you should get an error indicator from the
home position sensor were this the case.

 

[PC Medic]

You know, I've often wondered about that. With other printers, when
it does a cleaning cycle, it just hoses down a piece of paper with
ink. The canons, however, run through this long winded meditation
cycle with every power up that's supposed to be some sort of cleaning
cycle. What the heck does it do with the ink?
---------------------------------------------

It does not always fire ink during these cycles, but when it does like any
other it sends it to a waste ink area.

 

[Bill]

Is the generic ink to blame? The first four tanks for G&G worked just
fine - no problems

I doubt it.

Bad print head? I can order one for 47.07 + $5 shipping from Canon

I would guess the printhead is to blame.

What about where the print head sits when its off? Could something be
leeching up from the waste area? (or whatever the place is called that
the printer shoots the ink during a cleaning).

I doubt that as well. The head cleaning station uses a vacuum system to
draw ink through the printhead and then wipe the nozzles clear. The
printhead never touches a pad or anything that would cause colours to
mix.

 

[Bill]

You know, I've often wondered about that. With other printers, when
it does a cleaning cycle, it just hoses down a piece of paper with
ink. The canons, however, run through this long winded meditation
cycle with every power up that's supposed to be some sort of cleaning
cycle. What the heck does it do with the ink?

It sucks ink through the printhead and into a waste ink storage area.
The area has a pad around it to soak up the liquid.

When the printer goes through a cleaning cycle, the printhead is cleaned
with a plastic wiper blade to remove old residual ink from the surface
of the printhead. Then a small vacuum system draws a bit of ink through
the printhead to make sure it's flowing, and dumps it in the waste area.
The head is then wiped clear of any excess ink again, and the printer is
ready to go.

 

[PC Medic]

I doubt it.


I would guess the printhead is to blame.


I doubt that as well. The head cleaning station uses a vacuum system to
draw ink through the printhead and then wipe the nozzles clear. The
printhead never touches a pad or anything that would cause colours to
mix.

While I do agree this is probably not the issue, be aware that wicking
(leaching) can and has been the cause of this type of issue.
Stop and think about the purge station and how that vacuum is created. There
is in fact contact made with the printhead.

 

[Mike Brown]

Well I took the printer apart and go to the ink waste area - two hard but
pourous pieces sit in two rubber trays, lifting hard piece out of the tray
shows two holes in the bottom of the rubber trays. I washed those out.

Starting on the left and 3/4 the way across the bottom of the printer
housing is a large pad. The right most 1/4 of the printer also contains a
pad but its a bit lower. There two hoses off the bottom of the pump unit
that dump the waste ink into the pad. Mine was very saturated. I removed
the pad and washed it out - now I know where all my ink goes!

I found the two screws that hold the vaccum/waste area into the main printer
assembly. I removed the pump motor and rinsed the most of the pump area.
There was a small circuit board on the back that I didn't want to get wet.
Lots and lots of ink.

I also disabled the print head and rinsed that out clean.

I dried everything the best I could, re-assembled, installed new tanks, a
couple deep cleanings, prints really well again.

Could be a bad pump as was mentioned...

Could be the ink I suppose - maybe it doesn't dry the same and the Canon
brand...

Print head is working fine.

 

[David Chien]

The most obvious reason for this in the older Canon printers is that the
suction hoses connecting the pumps to the nozzle docking area has
degraded over time (made of rubber) and has cracked/split and has now
lost suction.

As a result, the pads under the nozzles can't suction the ink properly
away from the heads, and cross contamination of ink colors can occur,
even to the point where one ink cartridge starts to become discolored
due to the cross-mixing of inks.

This has been seen and documented in the Canon S450 printers, and can
occur in any Canon printer which has hoses connecting the pumps to the
nozzle pads.

---

The fix, which works in almost all cases, is to replace these tubes with
new ones. You can either ask Canon for them, or find any hobby store
and replace them with any flexible, liquid tubing (eg. from a lab,
there's lots of clear, flexible tubes that one can cut to length and
use). DO make sure that they're just a touch smaller than the ends
you'll fit them over to ensure a very tight fit that is vaccum tight -
here, you may need to use fine needle nose pliers to push the new tubing
over both connecting ends on the printer. take you're time and patience
and you'll be fine.

Here, we've simply replaced the tubing with standard, clear, lab-grade
flexible tubing found in most labs, and the printers work perfectly fine
after that.

Do note that you will have to replace all contaminated cartridges, and
that some cross contamination may still exist until you've run a few
hundred pages through to clear everything out.

 

[MCheu]

It does not always fire ink during these cycles, but when it does like any
other it sends it to a waste ink area.

So does this mean I need to eventually empty this waste tank?

 

[Mike Brown]

Just printed the google page - pretty much came out all blue.

I see another posting about cracked tubin on the vaccum hoses - worth a try!

 

[PC Medic]

So does this mean I need to eventually empty this waste tank?
---------------------------------------------

Depends how long you have the printer and how much you print.
The average owner will never need to have the waste ink service performed
even after several years of printing.
I myself have used Canon's for years and average about 3+ and 15,000 pages
through a printer before I move on to a new model and I have never had an
issue with a Waste Ink Tank warning.

 

[Bill]

So does this mean I need to eventually empty this waste tank?

Generally no...the ink dries up. It's not a storage tank, it's just a
pad in the bottom of the printer.

 

[Harry Kiri]

A very, very bad design flaw in these Canons -- can't believe they'd use
such cheap, rubber tubing that would naturally degrade in a few
months/years rather than higher quality tubing.

Why can't you believe it? It's a nice little earner for Canon, which
is, after all, the very reason for their existence.

They count on most people buying another printer, rather than trying to
repair ...

Regards,
Hughy

 

[Al Rudderham]

Why can't you believe it? It's a nice little earner for Canon, which
is, after all, the very reason for their existence.

They count on most people buying another printer, rather than trying to
repair ...

I'd doubt that selling you another printer is a "nice little earner".
Printers are sold using the old Gilette business model - "give the
razors away, make all the money on the sales of blades".

What Canon (and HP and Epson) want is for you to buy supplies, which
are very profitable. I'd bet they don't come close to breaking even
on the initial sale of the printer itself.

 

[Bill]

Why can't you believe it? It's a nice little earner for Canon, which
is, after all, the very reason for their existence.

Printer sales don't make much money, it's the consumables like ink and
paper where they rake in the huge profits.

They count on most people buying another printer, rather than trying to
repair ...

Hehehe...which is what I did...I bought an HP!

 

[PC Medic]

Why can't you believe it? It's a nice little earner for Canon, which
is, after all, the very reason for their existence.

They count on most people buying another printer, rather than trying to
repair ...

It is also hogwash that this is any kind of issue. I work on these printers
regularly and have not seen a purge issue with the tube since there C2500
MultiPass about 6 years back. During maintenance/repair the purge tubes I
encounter are all soft and pliable as they should be.

 

[Harry Kiri]

I'd doubt that selling you another printer is a "nice little earner".
Printers are sold using the old Gilette business model - "give the
razors away, make all the money on the sales of blades".

What Canon (and HP and Epson) want is for you to buy supplies, which
are very profitable. I'd bet they don't come close to breaking even
on the initial sale of the printer itself.

No doubt you are right on the supplies. Regarding their profit margin
on sales, I based my comment on my estimate of their cost of
manufacture, which is just that - a **rough estimate**.

Their printers are made from plastic, with a relatively very small metal
component. Mass produced (particularly in Asian countries), the
chassis/case costs are unlikely to exceed US$20. Costs of the PC boards
and SM components would be even less, with most of the components in any
model being shared across a wide range of their printers (not print
heads, of course). Heads? Likely to be in the order of $5 - $10 in
quantity. Asian assembly costs would probably be less than US$5 with
distribution a similar figure.

R & D (and marketing) would still be the biggest costs, but no one
outside Canon itself would be able to put a figure on it. My rough
guess would be about the same cost as the hardware.

So in the absence of any definitive statement from Canon, I *suspect*
they manage to sell their printers at a profit.

This in no way diminishes the mind-boggling (and unconscionable) profits
they make on inks.

Roll on the development of low cost hi res colour lasers.

Regards,
Hughy