Flashing cart light HP deskjet 940c

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J

john bates

I have a Deskjet 940c which has been working well for
the past 9 months with me refilling the carts when needed.
Two weeks ago the black ran out whilst printing text, so I
refilled as per usual. Then (as with Andrew 1234 a few days
ago) the black cart indicator light started flashing and has
done so for the past fortnight.

I read with interest the whole of Andrew's post below
and tried all the tips written there with no avail. No matter
what I do the bl.y thing goes on flashing!

I'll be very grateful for any ideas that might fix it.

John.
 
john bates said:
I have a Deskjet 940c which has been working well for
the past 9 months with me refilling the carts when needed.
Two weeks ago the black ran out whilst printing text, so I
refilled as per usual. Then (as with Andrew 1234 a few days
ago) the black cart indicator light started flashing and has
done so for the past fortnight.

I read with interest the whole of Andrew's post below
and tried all the tips written there with no avail. No matter
what I do the bl.y thing goes on flashing!

I'll be very grateful for any ideas that might fix it.

John.
Click to expand...

John
The cartrdige has probably failed.
Make sure you clean the contacts on both cartridges and the ones they mate with
in the printer.
When you open the top door, the carriage should move to the left, there is an
arrow on the top of the carriage and it should point to a frowning face. 3 dots
means the colour cartridge and 1 dot means the black one has failed.
Cartridges do fail, they were never designed to be refilled many times.
Tony
MS MVP Printing/Imaging
 
I have a Deskjet 940c which has been working well for
the past 9 months with me refilling the carts when needed.
Two weeks ago the black ran out whilst printing text, so I
refilled as per usual. Then (as with Andrew 1234 a few days
ago) the black cart indicator light started flashing and has
done so for the past fortnight.

I read with interest the whole of Andrew's post below
and tried all the tips written there with no avail. No matter
what I do the bl.y thing goes on flashing!

I'll be very grateful for any ideas that might fix it.

John.
Click to expand...

You may have read from one of the links provided by Bob Headrick

http://groups.google.com/group/comp...f1d37b6?lnk=gst&q=842&rnum=1#f4c45dba9f1d37b6

that the contacts on the gold foil of the cartridge and the cartridge
carrier may become whitish with crystalized contact lubricant. (That
wasn't my problem, though).

I looked closely at the black ink cartridge that failed for me, and it
seemed to be slightly darker than shiny copper. Following a
recommendation, I used a pencil eraser to rub the foil contacts on the
ink cartridge (carefully remove any rubber particles with a soft
cloth) and it seemed to rub off the dark haze. I don't know if this
"worked" because this is not now a cartridge that I am using.

This recommendation went on to use the eraser, if necessary, to clean
the contacts in the cartridge carrier. I haven't tried this. If I did
try it, I would be very careful to not bend the little contact points
in the carrier.
 
Tony said:
John
The cartrdige has probably failed.
Make sure you clean the contacts on both cartridges and the ones they mate
with
in the printer.
When you open the top door, the carriage should move to the left, there is
an
arrow on the top of the carriage and it should point to a frowning face. 3
dots
means the colour cartridge and 1 dot means the black one has failed.
Cartridges do fail, they were never designed to be refilled many times.
Tony
MS MVP Printing/Imaging
Click to expand...

Thanks Tony, but I 've tried 2 other carts that I bought from Incyle, still
no joy.
John.
 
I have a Deskjet 940c which has been working well for
the past 9 months with me refilling the carts when needed.
Two weeks ago the black ran out whilst printing text, so I
refilled as per usual. Then (as with Andrew 1234 a few days
ago) the black cart indicator light started flashing and has
done so for the past fortnight.

I read with interest the whole of Andrew's post below
and tried all the tips written there with no avail. No matter
what I do the bl.y thing goes on flashing!

I'll be very grateful for any ideas that might fix it.

John.
Click to expand...

Those #45 black carts have a way of turning bad all of a sudden. They
can't be refilled forever. I had a couple of them quit early when I
refilled them with generic dye based ink instead of pigmented. Maybe
there was some incompatibility with the ink you were using.
 
john bates said:
Thanks Tony, but I 've tried 2 other carts that I bought from Incyle, still
no joy.
John.
Click to expand...

If you replaced the correct (failing) cartridge then there is a possibility
that the printer has failed but this particular failure is extremely rare.
Cleaning the contacts in the printer is well worth a try but do it for both
cartridges. It is impossible for the ink to cause this problem, the printer and
the printhead in the cartridge have no way to know what ink is present.
Have you tried replacing both cartridges? Some models can get confused about
which cartridge has failed.

Tony
MS MVP Printing/Imaging
 
john said:
I have a Deskjet 940c which has been working well for
the past 9 months with me refilling the carts when needed.
Two weeks ago the black ran out whilst printing text, so I
refilled as per usual. Then (as with Andrew 1234 a few days
ago) the black cart indicator light started flashing and has
done so for the past fortnight.

I read with interest the whole of Andrew's post below
and tried all the tips written there with no avail. No matter
what I do the bl.y thing goes on flashing!

I'll be very grateful for any ideas that might fix it.

John.
Click to expand...
Try a hard reset.
Turn on printer power.
Open printer cover, remove both cartridges, close clamps and cover.
Unplug power cord from printer.
Wait 30 seconds.
Plug power cord back into printer.
Open top cover and reinsert both cartridges.
Turn on printer power.
 
Andrew1243 wrote:

The eventual link to HP says,
"Ink manufacturing uses a lubricant coating to attach the electrical
contacts on the cartridges."

Wha?????????
A lubricant as a glue??? (Was this writer passing a brain stone?)

"HP has discovered that in a small number of cases, the lubricant may
form a crystalline material that blocks electrical impulses between the
cartridge contacts and the contacts of the cradle inside the printing unit."

Hmmm. I've never seen any contact preparation that forms a crystalline
residue. However, I'm puzzled that printer manufacturers do not
recommend the use of trusted liquids like alcohols to clean crud off
these contacts. And I never even see them recommend the use of the
trusted contact cleaning fluids and cleaner/lubricants that are probably
the most frequently-used tools in electronics repair shops. But printer
makers recommend "clean cloths" and "water." I've never seen any
technician in my life do this. What gives?

However, I am used to seeing user manuals repeat the same goofy
incorrect garbage year in and year out.

Clean unprinted paper (or card stock) is often used to clean precision
contacts.
 
Richard said:
Andrew1243 wrote:

The eventual link to HP says,
"Ink manufacturing uses a lubricant coating to attach the electrical
contacts on the cartridges."

Wha?????????
A lubricant as a glue??? (Was this writer passing a brain stone?)

"HP has discovered that in a small number of cases, the lubricant may
form a crystalline material that blocks electrical impulses between the
cartridge contacts and the contacts of the cradle inside the printing
unit."

Hmmm. I've never seen any contact preparation that forms a crystalline
residue. However, I'm puzzled that printer manufacturers do not
recommend the use of trusted liquids like alcohols to clean crud off
these contacts. And I never even see them recommend the use of the
trusted contact cleaning fluids and cleaner/lubricants that are probably
the most frequently-used tools in electronics repair shops. But printer
makers recommend "clean cloths" and "water." I've never seen any
technician in my life do this. What gives?

However, I am used to seeing user manuals repeat the same goofy
incorrect garbage year in and year out.

Clean unprinted paper (or card stock) is often used to clean precision
contacts.
Click to expand...
Ever heard of dielectric Si grease? I got a Canon dSLR off a guy who
claimed it just quit all of sudden and it won't do anything for almost
free. The problem was battery was not making a good contacst within the
compartment. Rest is history. I got a good caemra for next to nothing.
I resold it for big profit, LOL! No, I gave it to my daughter. You can
buy special cleaning fabric or liquid gold(to revive contacts) from
electronics parts store or guitar shop where service dept. is.
 
Tony said:
Ever heard of dielectric Si grease? I got a Canon dSLR off a guy who
claimed it just quit all of sudden and it won't do anything for almost
free. The problem was battery was not making a good contacst within the
compartment. Rest is history. I got a good caemra for next to nothing.
I resold it for big profit, LOL! No, I gave it to my daughter. You can
buy special cleaning fabric or liquid gold(to revive contacts) from
electronics parts store or guitar shop where service dept. is.
Click to expand...

Yeah. But using dielectric Si grease as an adhesive for contact strips?

Of course, you're talking sense.

Richard
 
The eventual link to HP says,
"Ink manufacturing uses a lubricant coating to attach the electrical
contacts on the cartridges."
Wha?????????
A lubricant as a glue??? (Was this writer passing a brain stone?)
Click to expand...

No, it needs a lubricant that does not interfere with the conductivity, not
a glue. As the cartrdige is slid into the carriage there is a metal to
metal sliding action. If you use alcohol or other solvents to remove all
lubricants from the pads and pogo pins in the printer you would risk
damaging the pads or the pogo pins when the cartrdige is installed. It may
not happen with the first insertion but over the life of the printer would
cause problems. I have seen this happen, both in damaging cartridges as
well as printers before the lube process was added to the manufacturing for
the #41 and #45 cartrdiges.
"HP has discovered that in a small number of cases, the lubricant may form
a crystalline material that blocks electrical impulses between the
cartridge contacts and the contacts of the cradle inside the printing
unit."
Hmmm. I've never seen any contact preparation that forms a crystalline
residue.
Click to expand...

Just because you have not seen it does not mean it does not happen.
However, I'm puzzled that printer manufacturers do not recommend the use
of trusted liquids like alcohols to clean crud off these contacts. And I
never even see them recommend the use of the trusted contact cleaning
fluids and cleaner/lubricants that are probably the most frequently-used
tools in electronics repair shops. But printer makers recommend "clean
cloths" and "water." I've never seen any technician in my life do this.
What gives?
Click to expand...

See above, you do not want the contacts to be squeaky clean. You also do
not want to recommend paper that may leave fibers on the contacts. There are
lots of system issues that would not be obvious to a casual observer.

- Bob Headrick, MS MVP Printing/Imaging
 
Bob said:
No, it needs a lubricant that does not interfere with the conductivity,
not a glue. As the cartrdige is slid into the carriage there is a metal
to metal sliding action. If you use alcohol or other solvents to remove
all lubricants from the pads and pogo pins in the printer you would risk
damaging the pads or the pogo pins when the cartrdige is installed. It
may not happen with the first insertion but over the life of the printer
would cause problems. I have seen this happen, both in damaging
cartridges as well as printers before the lube process was added to the
manufacturing for the #41 and #45 cartrdiges.


Just because you have not seen it does not mean it does not happen.


See above, you do not want the contacts to be squeaky clean. You also
do not want to recommend paper that may leave fibers on the contacts.
There are lots of system issues that would not be obvious to a casual
observer.

- Bob Headrick, MS MVP Printing/Imaging
Click to expand...

Thanks for clearing this up, Bob.
My initial problem was caused by the following statement:
"...uses a lubricant coating to attach the electrical contacts..."
In other words, a glue that's a lubricant. Dunno -- when I do
documentation, stuff like this generates a question, as in: "Wha???????"
Voodoo. It would never get by me.
In my world, a lubricant coating would typically cause the contacts to
fall off. I'd need someone to explain this in order to believe it.

This is like anti-glare coatings on monitors, in which the manufacturer
says to clean the tube face with a dry cloth or maybe some water. So, I
ask what they recommend -- they say a dry cloth. So I ask what they use
to clean the screen at the factory, and then I get an answer like "Windex."

Well, last week I attempted to remove the anti-glare coating on a
Trinitron screen. I worked like hell with a green pot scrubber, then
switched in desperation to the black one -- the kind that you use to
scrub concrete and barbeue grills. Finally, with this, strong alcohol,
and a lot of sweat, I managed to get one small patch down to bare glass.

Or then there was the time I tried to demagnetize a floppy disk on
purpose; I wanted to kill the format pattern. So, I put the disk on a
power transformer and turned on the juice. It didn't work. I couldn't
erase the disk. Maybe I should have soaked it in Southern Comfort...

Thanks for your explanation. I'll select a good contact preservative
(cleaner-lubricant)from my workbench and do my HP cartridges and -- what
did you call them -- "pogo pins?" (What = "pogo" and why? The plot
thickens.)

Richard
 
Al Bundy said:
Those #45 black carts have a way of turning bad all of a sudden. They
can't be refilled forever. I had a couple of them quit early when I
refilled them with generic dye based ink instead of pigmented. Maybe
there was some incompatibility with the ink you were using.
Click to expand...

Funny you should say that! I did add some of another ink I bought in
a kit fron Asda. Might have been the cause initially, but I've since used
new carts BW and Col.
Many thanks.
John.
 
tomcas said:
Try a hard reset.
Turn on printer power.
Open printer cover, remove both cartridges, close clamps and cover.
Unplug power cord from printer.
Wait 30 seconds.
Plug power cord back into printer.
Open top cover and reinsert both cartridges.
Turn on printer power.
Click to expand...

Just done all that again, probably for the tenth time.. Still it flashes.
Last try - Hose it down in the garden then buy a new one.
Thanks a lot. John.
 
Andrew1243 said:
You may have read from one of the links provided by Bob Headrick

http://groups.google.com/group/comp...f1d37b6?lnk=gst&q=842&rnum=1#f4c45dba9f1d37b6

that the contacts on the gold foil of the cartridge and the cartridge
carrier may become whitish with crystalized contact lubricant. (That
wasn't my problem, though).

I looked closely at the black ink cartridge that failed for me, and it
seemed to be slightly darker than shiny copper. Following a
recommendation, I used a pencil eraser to rub the foil contacts on the
ink cartridge (carefully remove any rubber particles with a soft
cloth) and it seemed to rub off the dark haze. I don't know if this
"worked" because this is not now a cartridge that I am using.

This recommendation went on to use the eraser, if necessary, to clean
the contacts in the cartridge carrier. I haven't tried this. If I did
try it, I would be very careful to not bend the little contact points
in the carrier.
Click to expand...

Hi Andrew,
Many thanks for trying to help.
I've spent a lot of the past two weeks doing all the things I've read
about over and over again, as if teasing me it still flashes away.
Before I throw it away, I'm going to take it outside hose it down
dry it out and start again.
John.
 
Al Bundy said:
Those #45 black carts have a way of turning bad all of a sudden. They
can't be refilled forever. I had a couple of them quit early when I
refilled them with generic dye based ink instead of pigmented. Maybe
there was some incompatibility with the ink you were using.
Click to expand...

Thanks Al.
I just sent you a reply but it didn't turn up!
Strange, but for the first time I did add some ink that was in a kit
I bought from Asda... But since then I've put 2 new ones in, Col.
and BW. I won't do it again though. Thanks John.
 
Thanks for your explanation. I'll select a good contact preservative
(cleaner-lubricant)from my workbench and do my HP cartridges and -- what
did you call them -- "pogo pins?" (What = "pogo" and why? The plot
thickens.)
Click to expand...

They are called pogo pins because the contacts in the printer are made of a
three piece telescoping gold sleeve, gold spring and plunger, something like
a miniature pogo stick. This entire discussion applies to the cartridges and
printers in the DeskJet 700, 800 and 900 series. Earlier and later printers
use a series of raised bumps on the printer side and do not use contact
lubrication.

Do not use much lube - it should be barely detectible on the pads. More
could cause the cartridge pads to collect dust or paper fibers which can
also cause interconnect issues.

Regards,
Bob Headrick, MS MVP Printing/Imaging
 
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