HP 78s

[unclefalter]

Hi there,

I currently do hand-filling of inkjets as a sideline to my computer business. I have had a lot of problems recently with HP 78s, 25s, 23s, etc. I believe the problem is air, since print problems are not consistent -- it will print fine one or two pages and then streaks will appear, then i vaccuum a bit, prints fine again, then streaks, etc -- but I'm unsure how to solve the issue.

Anyone have a good technique for us ancient hand-fillers? I don't quite have $5000 to spend on a vaccuum refill system just yet, much though I would like to. If you have a working technique you'd like to share in detail please do. We were doing quite well with 78s etc for quite a while.. just recently it has been non-stop problems.

Thanks again!

 

[Grandad35]

Unclefalter,

Welcome to the forum.

Look at post #54 in (http://www.nifty-stuff.com/forum/viewtopic.php?id=28&p=6) for a short discussion on "slinging" HP carts. This worked well for me on 56, 57 and 58 carts. It can be very difficult to "fix" a HP cart that has been run empty. The best solution is to never let run any color run empty, but this is obviously not under your control.

I assume that you have a "hand priming tool" to help pull air from the cart immediately after refilling.

You might also want to look at posts made by Craig Ross - he had a lot of helpful hints for refilling.

 

[Manuchau]

I refill cartridges as part of my living, and have a 99% success rate with these, so I know of your problem, and indeed, it is air.

Here is the technique.

1) Fold a paper towel 3-4 times and with a rubber band, seal it to the bottom of the cartridge.
2) Inject your inks into the 3 cylinders, and do not overfill.
3) Now, the important step which guarantees success. Remove the paper towel, and hold the cartridge upside down so that you're looking at the nozzles. With a tiny plastic bottle or plastic tube tightly inserted into the 1st chamber, squeeze until the air bubbles are gone, and the ink runs freely. Keep a paper towel handy to mop up any excess ink. Repeat with the other 2 chambers. When you squeeze the bottle and the ink runs freely from all 3 chambers, you're done!! Success every time.
Run a test page, and head cleaning...you'll see. If you're confused, contact me and I'll walk you through it.

The first few might be tough, but after a while, you'll get the hang of it and will have 100% success. Good luck!!

 

[Nifty]

Manuchau, very interesting idea. I hope unclefalter tries it and reports back!

 

[Manuchau]

I hope so....it's a perfect method, and for those people who are just starting to refill, this model can be difficult.

 

[unclefalter]

Hi there,

Sorry to be absent so long.. got sick with a really nasty flu.

Anyway, I will try that method now that I'm up and going again. Really appreciate the help. Can I use a small air compressor in place of the plastic bottle, etc? Where were you getting the bottle/tube from, just in case I have to find one??

Sounds like a great method. I'll try anything at this point.

One other question -- how do you ensure you don't inject too much ink (ie.. guard against accidentally overfilling a chamber that might be mostly full, even though the others are empty)

Thanks again!