Canon S400 printhead- how do I repair it?

[Jacob Jackson]

Ok, I've had this Canon S400 for a couple of years now and, even when using
refill kits with success, it seems that I still end up replacing the entire
$50 print head at least once a year (even after soaking the head in
solution, etc etc). It is my understanding that there is a resistor array
that heats the ink before exiting the head and that is what burns out. Now,
being technically inclined as I am, plus the fact that I'm tired of spending
$50 bucks a pop on a glorified piece of plastic, I'd like to try replacing
or modifying this array myself. Can anyone tell me where this resistor
array is located? At first I thought it might be near the series of small
tubes that carry the ink from the cartridge to the paper, but I don't see
it. There is also an area on the bottom of the printhead that is covered
with black epoxy. I removed the epoxy on a previous head and didn't see the
resistors. Of course, ultimately, a schematic diagram of the head and
surrounding circuitry would show the array, but I'm betting one isn't
available, or is it?

Any help would be greatly appreciated,
Jacob

 

[David]

There is an integrated circuit under one small epoxy part of the print head,
the resistor array is micro-tubular resistors that are formed as part of the
print head nozzle jets. It is highly unlikely that you will have a
microscope of high enough magnification and the tools required to perform
any kind of repair at that level.

Replacement is the option. Make sure the ink you are using is the EXACT oem
correct type of ink as the wrong type of ink can cause problems.

David

 

[Jacob Jackson]

Hi David,

Interestingly enough, on a whim, I decided to refill the black cartridge.
It had only decreased to 40% of full, but I felt I had nothing to loose. I
did notice some back resistance while filling, maybe because I have mixed
different inks in the past. Anyway, I reinstalled into the printhead and it
now seems to be working again. I've read of similar experiences lately- not
letting the ink decrease to less than 50%- but I wasn't sure if this would
have anything to do with it or not. Apparently so, although mixing
different types probably hasn't helped either.

JJ

 

[Jim Yanik]

There is an integrated circuit under one small epoxy part of the print
head, the resistor array is micro-tubular resistors that are formed as
part of the print head nozzle jets. It is highly unlikely that you
will have a microscope of high enough magnification and the tools
required to perform any kind of repair at that level.

Replacement is the option. Make sure the ink you are using is the
EXACT oem correct type of ink as the wrong type of ink can cause
problems.

David

I believe using one of those refill kits was the cause of the demise of my
Canon BJC-620 printhead.First,the cartridges after refill drained very
rapidly thru the printhead,then I got a 'printhead failure' screen message.
And the 'black' ink from the kit faded to brown,even in low light
conditions.

NEVER again.