Unclogging Canon Printheads

[JimDandy]

Latest:

First two points:

1) I cleaned both pads as best I could. The pigment black pad has permanent splotches of black here and there on one side and a line of black extending almost all the way down the middle on the other. I seem to be able to blow or suck air through it. The other pad cleaned up nicely with no splotches.
2) Still seems that without the pad, the wells both drain something when I run a clean cycle (even if it's just pigment black, both wells look like they drain some).

Followup

1) I still don't think this has anything to do with the printhead or cartridge (I now have 2 of each, and it's the same behavior)
4) I've purchased the PDF manual, and should have it soon

And now, I tried my own method of unclogging the tubes, which looks like it's failed. I took a finer gauge blunt syringe needle, bent it more than 45 degrees on a curve, filled my syringe with ammonia cleaner, and tried forcing it into all the well ports. In all cases, fluid shot back up and filled the wells. I did this for about 10 or 15 minutes off and on while I waited for the pads to soak. I also sucked fluid back out from the wells and tried to do the same from the ports. My impression is that all of the ports are closed at the bottom when the printer isn't cycling, so this probably isn't a real solution, but I'd be interested to hear otherwise (if you think I should be able to shoot fluid through the tubes when the printer's unplugged).

At this point, I guess I'm looking at stripping the thing down once I have the manual and looking for a clog, because I'm still where I started with no printing of pigment black. This must be a really bad clog or an entirely disconnected drain tube. I'm not sure if it's time to just get rid of the thing, but I guess I'll give a fix one more go.

 

[ghwellsjr]

You don't sound too sure about being able to suck air through the purge pads. They should offer practically no resistance.

You also don't sound to sure about the ability of the purge pump to suck away liquid in the purge pad wells. It should be essentially empty of all ink.

Once you get the purge pads clean, you can put them back in their holders and repeat the test with the pads in place. If the surface after you put liquid on them remains glossy after a cleaning cycle, then you can look further down. If the surface is rough, then you know the purge pump is working.

 

[JimDandy]

You don't sound too sure about being able to suck air through the purge pads. They should offer practically no resistance.

Again, it's an issue of not being sure air isn't going around the pad, but I'm pretty sure air's going through. I think the only alternative for comparison would be to order (a) new one(s). That may be a good idea, at this point.

You also don't sound to sure about the ability of the purge pump to suck away liquid in the purge pad wells. It should be essentially empty of all ink.

Liquid does go down during the cycle

Once you get the purge pads clean, you can put them back in their holders and repeat the test with the pads in place. If the surface after you put liquid on them remains glossy after a cleaning cycle, then you can look further down. If the surface is rough, then you know the purge pump is working.

I would say it appears to be working, except when I move on to printing. Again, I think everything else is pretty much ruled out, but I can't really say for sure.

 

[ghwellsjr]

I wouldn't take the printer apart as the conclusion is the purge system is working, especially if you can see any black ink on the purge pad after doing a cleaning.

Looking back at post #34, I would conclude that you damaged your first print head in your attempt to clean it and it damaged your printer which is why your second print head does not work. The risk is that your second print head may also be damaged which you'll never know unless you put it in another printer but that could damage the other printer. Personally, I wouldn't try any more to fix this printer or to use either of your print heads in another printer.

You can continue to use your printer by telling it you are printing on matte paper whenever you want to print on plain paper.

 

[JimDandy]

I wouldn't take the printer apart as the conclusion is the purge system is working, especially if you can see any black ink on the purge pad after doing a cleaning.

Looking back at post #34, I would conclude that you damaged your first print head in your attempt to clean it and it damaged your printer...

Thanks for the followup. This is really bad news, if you're right. Can I ask how you think I may have damaged the printer with the first printhead? Would this be an electrical componenet problem of some kind? The way it's been behaving, it almost seemed to me that the computer just wasn't communicating with the pigment black cartridge, but that didn't really make any sense.

I know from past experience what can happen with printheads. I successfully cleaned the PH in my i850 for years, then the printer started to throw errors, and it became clear that the PH was toast. Hence the MP610, since it cost marginally more than a PH for the i850. But in this case, the printer isn't reporting any errors, the ink level reporting is fine, all cart lights are on, etc.

I hate to think of relegating this to the landfill. I suppose it couldn't hurt to buy a purge pad, could it? Or do you think the purge pump is damaged from being dry?

 

[ghwellsjr]

If the purge unit is working (do you see black ink on the purge pad after doing a cleaning?) and your second refurbished print head was not defective, then the only logical conclusion is that the printer is damaged. It is also possible that the second print head came damaged but it sounds to me like a downward spiral trying to get to the bottom of this.

In post #34 when you reported using all kinds of cleaners on your print head, were you doing that outside of the printer? I'm going to assume so and that is when damage to print heads usually occurs. I have done the same thing except in my case, the printer wouldn't print anything, not just the pigment black as in your case.

 

[JimDandy]

I'm still wondering what could cause this symptom if not a bad printhead, cartridge, or purge. Can you elaborate?

Yes, all cleaning of the printhead has been outside the printer. Thing is, I've done it multiple times with no effect on the four dye colors so, like you say, it doesn't really suggest a damaged printhead. Also, I've only used 3 things on the printheads - warm water, ammonia-based window cleaner, and isopropyl. I've always finished cleaning with water.

 

[JimDandy]

If the purge unit is working (do you see black ink on the purge pad after doing a cleaning?)

So, going back again to the printer with everything back in place and both purge pads recently cleaned, I did just try another regular pigment black clean cycle. The pad looks the same before and after, which is kind of salt-and-peppery, meaning I can still see white on it. In other words, it looks like it really isn't drawing down black ink. I think I might read up on disassembly (now that I have that guide) and ask about buying a set of purge pads from Canon. I guess I'm still suspecting a clog in the purge system for pigment black. The odd thing is, it looks like there's just one tube for the entire purge assembly, so I'm not sure if what I'm saying makes sense. Could there be a clog affecting just pigment black?

 

[ghwellsjr]

Yes, there are separate tubes for the pigment black ink and for all the other dye inks. Here are pictures of a purge pump from another printer. You can easily see the two tubes coming out of the bottom of the purge pump. The one on the left that exits at a diagonal is for the pigment black and the one coming straight down is for the dye inks. Where did you see just one tube? Was it above or below the purge pump? There are actually two tubes coming out of each pad tray on the top (a total of four for both pads) going down into the purge pump. I don't know what the second set is for.

 

[JimDandy]

I was just looking at the parts list (shows one tube). Haven't opened the printer yet.