Nice way to 'unclog' print heads...?

[BWlover]

Maybe something you can use. Or want to comment on since I am fairly new at this.
In my attempt to convert a S800 printer into a 100% black and white printer, the Photo Magenta position did not print at all anymore (I had an ink flow problem in one of my catridges: I think it can be blamed on using the Durchstifchmethod - the air is coming from the hole instead of building up some underpressure to pump the ink from the ink chamber - I think I like the hole-in-the-top method better although I am worried that leakage can occur much more quickly). After fixing the ink flow problem, amongst others by switching cartridges (the advantage of only using black ink...), I still did not get any printing from the PM head. I thought I ruined the printer like it is said in so many posts. Well, first of all, I discovered that you can print for a hell of a long time without ink: while trying to get it going, not printing anything, it was NOT ruined....!!! Good news!
So how did I get it running again? Thinking it was ruined anyhow, I messed around a bit. I found at that this is a VERY good way to get it going again:
1. take out the print head and take out the catridge which does not print
2. take a plastic pipet and fill it with the respective ink
3. press it firmly against the iron filter in your print head
4. squeeze out ink until it start dripping out of the bottom of the print head below
5. clean up the ink which is spilled within the print head while doing this (it is unavoidable) with some q-tips or tissues. I tried not to touch the filter although I don't really know whether it is important...
As long as you take care that there is some ink coming out below, it will work.
So, in conclusion, I suspect (don't know it for certain yet) that not clogging but ink flow is the main issue when a head is not printing.
Maybe something for those of you out there to try if your print head is failing...? Let me know your experiences!

 

[ghwellsjr]

This technique has been reported on here in the forums and I used it to unclog a print head but I failed to let the print head dry for two days and it not only killed the print head, it killed my printer. I'm also concerned that too much force can damage the internal seals and you can end up with the different color inks contaminating each other.

 

[mikling]

There are sometimes certain techniques which have worked for some but that does not mean that what is being purported is good. This is one of them. The bottomplate is bonded underneath to a ceramic mould by adhesive. When the printhead gets old, the adhesive can/will weaken. If you pressurize the internals too much it might be enough to undo the adhesive and allow ink to cross contaminate inside. Pressurizing a Canon head is not a good idea at all for this reason.

So like ghwellsjr says it happened to him but it may not happen to everyone so you do so at your own risk especially the fundamentals of what is being done is wrong.

 

[qwertydude]

That's why when I had to do this I use a tube that fits tightly and suck cleaning solution from the bottom, make sure the tube is long so you don't end up drinking ink lol. It makes more sense too since the clog is always on the inside of the printhead why try to blow it out?

 

[BWlover]

Thanks for the warning. I my case I really think it was not a case of clogging but just ink flow: the pressure I applied was really not very high. I had the strong feeling that there was nothing in the channels but filling it with ink helped a lot. Maybe a general advice could be then to try this without a lot of pressure just to get the ink going again...

 

[leo8088]

Use a flexible translucent water hose from hardware stores with a proper internal diameter (ID) attached to a syringe with the needle removed. This worked very well for me. Need to refrain yourself by not applying too much pressure. The good feature about this is you can push and pull the plunger and apply pressure or vacuum to the print head. If you push it is applying positive pressure to the print head. If you pull the plunger it sucks from the print head. It works really really well.