HP 78s Part II

[unclefalter]

Hi there,

Okay, I tried the method suggested to me in the last thread, and it does seem to improve things.

However, there are two problems I'm running into. One is, I can't seem to prevent corruption of the yellow tank by the magenta, when I have the cartridge upside down and I'm forcing air into it to clear air from around the printhead. The second is, I don't know how to tell how much ink to put in each chamber, so I think maybe the first problem might be being caused by overfillinget rather than ink leaking over during the air-purge process.

The process suggested produces a good test page a few times, but eventually the colour corruption thing happens as described, or you start getting bands of much lighter color in the print test patterns (so like, 75% of the horizontal band for a given color is correct, and then 25% is noticeably lighter).

Any advice on how to judge ink amounts and stop further problems would be greatly appreciated!

Thanks again for all the help so far!

 

[Manuchau]

Hi again..

Sounds like a classic case of overfilling the chambers. As an experiment, only use 6-7 mls in each chamber the next time you refill, and remember... It's always better to underfill - always!

If you want to make sure all chambers are empty before you refill, then get yourself
a bottom-suction totol from any ink supplier (about $3.00-$5.00). Empty the cylinders, then refill.
Remember, when you are using the plastic bottle to slowly purge air from the chambers to keep a paper towel handy to mop up the ink as it emerges from the print head. This will keep it from migrating into the other chambers.

Stick with it...you're getting better. It WILL take practice..and eventually will become easy. When I started refilling for a living, I found these were the most difficult to do. Now, they are no problem. The same thing will happen to you.

Best of luck, and keep asking questions!!!

 

[unclefalter]

Hey there...

Well, I'm just not sure I'm doing it right yet -- what I've been doing is using a 30cc syringe, the plastic end squeezed into the chamber. Then I 'inject' air, watch as the bubbles come out, and then the ink starts to flow. Mop it up, repeat on each chamber, etc etc. Blot it to check ink flow, no problem. Then I insert it in the printer, and either there's lines, or one color has completely stopped, or so on. So I remove it, try to purge the air again as described.. ink flows again, this time maybe it prints a bit better.. but then it gradually locks up again. I've cut the ink amount in half, so I'm pretty sure it's not overfilling.

Is it maybe the syringe is putting too much air in there? Maybe a syringe is the wrong device? If you could give me an example of what you're using (pic would be great, but I wouldn't ask you to go to the trouble).. for air purging.. that might help.

Thanks again, I think I'm getting it.. it's just figuring out why it keeps locking up after the ink was flowing ok.

 

[Manuchau]

If it stops flowing, the problem is air in the nozzles. A syringe does not give you a tight seal in the filling station, so more air is getting in - a definite no-no. You'd be better off getting some small plastic tubing which just fits into the opening, and then slowly blowing into it until all bubbles are gone. This you can often find at hardware stores, or aquarium suppliers...or a pet store.
The small bottle with the long, skinny neck that I use came from a glue sample bottle...I don't know where you could find one. I'd scan a pic here, but haven't found the way to uplload pictures here. Would you know how to upload here?
Or, I could e-mail you a photo if you prefer.

 

[Grandad35]

Manuchau,

Here's a link on how to upload images.
http://www.nifty-stuff.com/forum/viewtopic.php?id=36

 

[unclefalter]

Hey there..

Yeah if you can upload a pic that'd be awesome.

What I use is a syringe (no needle), which I've filed the end of down to a cone, so it just barely squeezes into the chamber. Then I squeeze it and bubbles come up, then free flowing ink.. and then sometimes it locks up again after that.

Just out of curiousity.. bottle or syringe.. aren't they both putting air into the chamber?

Brad

 

[nick38]

HI Unclefalter,
Do you weigh the hp78 cartridge to see if it is empty before you refill?
How do you get the ink out of the cartridge?if there is still ink in the cartridge?
Nick

 

[Manuchau]

Here's a pic of the small, narrow-necked bottle I use when refilling the 78s.
It's q poor quality image, but uou'll get the idea. In the meantime, have you found any snall plastic tubing?

That works just as well.

http://www.nifty-stuff.com/img/files/smbottle.jpg

 

[brian]

Hi

The way i refill the hp 78 is i put 8ml in my syringe use a long 2inch needle so the ink goes into the bottom of the cartridge, stick the needle into the the cartridge then turn the cartridge upside down and slowly inject the ink, do that for all three colours, i usualy to the yellow first, then i get a plastic needle on a spare syringe then turn the cartridge upside down again and blow air into the top of each chamber to you get a good flow of ink coming out the printhead, then blot the cartidge on some toilet tissue to the three colours are coming out good.

Regards
Brian
sales@aussieinkjet.net.au

 

[stavstav]

okay what you can do is #1 take the needle off syringe stick in hole of appropriate color chamber and inject air pressure into it causing the ink clog or air out the head.
#2 what i do with the red especially on these is you must use sharp needle cut thru sponge towards the very front of the cartridge near head. inject ink leave airhole at top (unless you want ink explosion!!) and the air bubbles and ink will flow out when ink starts flowing out with NO air bubbles then stop. (put little container at bottom to save exess ink). set in on-back position for about 15 mins allow ink to soak into sponges at least that long i put them in a sealed bag for 30 mins.
okay after that if you stand straight up the cartridge and if it leaks you have overfilled. turn cartridge upside down allow exess ink to drip out. or you can draw out with syringe from top or both. when you turn it upright and none leaks or very little, but when you touch to paper towel all 3 colors flow out, you have succeded. put in printer

it makes a big difference how dried out are the sponges as to if you will overfill or not

if the cartridges were very old and or dried out i put the very tip of ink head in very shallow hot water after refilling and letting soak into sponges of course, after this you will force the new ink thru with a bit of air pressure. seems to work most the time

i add a tiny bit of propylene glycol to the color ink to avoid it evaporating from the chambers

good luck mang