Starved for magenta, HP C309a

[ThrillaMozilla]

I thought this was a cartridge problem, but it occurs with two cartridges. The printer starves for magenta in big, solid areas, but is OK for more ordinary prints. Usually then it's not long before magenta conks out completely. A cleaning cycle restores it. It's almost as if only a cleaning cycle will feed ink. Here's a test print on paper.

This printer is a few months old, with about 600 prints on the clock. Suggestions?

 

[turbguy]

Could be a clog in the passageways of the print head. Is it still under warranty??

 

[turbguy]

BTW, a cleaning cycle pulls ink through the print head and probably refills the volume adjacent to the nozzles (at least for a while).

 

[ThrillaMozilla]

If the print head were clogged, would it print normally? This prints normally after a cleaning cycle and then quits. Or is there another place where it can clog, upstream from the nozzles? I'm unsure of the structure of these print heads.

I'm not sure whether it's under warranty, and I'm not sure that's a great option anyway. It would cost me $60 to put in a set of new OEM cartridges, plus shipping, plus waiting, plus they might still figure out that I had refilled, void the warranty, and charge me return shipping and handling.

 

[PeterBJ]

The HP print head looks very similar to Canon print heads, so I assume the inner workings are the same, and narrow channels lead from the ink inlets to the nozzle unit at the bottom of the print head.

If nozzles were clogged I think the pattern would be constant, so my guess is that the narrow channel for magenta in the upper black part of the print head is partly clogged. Maybe a cleaning cartridge made by filling a cartridge with a mixture of Windex and ink might clear the clogging by doing some nozzle cleaning? If your cartridges has been refilled often, then maybe the magenta cartridges are clogged and need flushing? Even if it is expensive you could try a new OEM magenta cartridge. If the OEM cartridge prints OK, you know that the print head is OK and the cartridges need flushing. If it does not make any difference you know that the problem is in the print head.

Edit: If the cartridge vent is blocked, maybe from overfilling the cartridge, I think that would give the same problems. I'm assuming the cartridges are also very similar to Canon cartridges.

Good luck with the troubleshooting.
Peter

 

[ThrillaMozilla]

So there is some sort of upper passage in the print head that can clog? That makes a lot of sense.

No, I don't think the cartridges are blocked in any way. They're quite moist at the outlet if you touch them with a tissue, and ink flows pretty freely. The vents aren't blocked. I'm sure of that. Both cartridges have been refilled exactly once, and each has a different first-rate brand of ink. Although both cartridges may have dried out before refilling, both were purged before refilling.

Good point about the OEM cartridge. It would only cost a few bucks to try that.

There's one thing I don't understand, though. How could the top of the print head be clogged? The colored cartridges have had only dye, and it has been through many cleaning cycles with dye ink. Each time quite a bit of ink flowed through. How could it still be clogged or getting clogged?

Could there be some foreign particles in there? If so, how could I get them out? Can the head be backflushed by drawing fluid through backwards?

 

[PeterBJ]

In a Canon print head these passages are less than one millimetre in diameter, so they can clog.

Some years ago I was given a Pixma 4000 with a badly clogged print head. This printer had been used with very cheap 3rd party cartridges from E-bay. I took the print head apart and found out that some passages for dye ink in the upper part were clogged. Using a syringe and an adapter I forced water through the passages from the ink inlet side, and managed to get the passages open again. I then put the print head back together and more gently squeezed water through the print head from the ink inlets. After a lot of cleaning I finally got the print head unclogged.

I do not recommend this procedure, I didn't know then that a defective print head could burn out the logic board in the printer. I learned that later by ruining a Pixma 5000 by putting back a print head that was not completely dry. I guess I was very lucky with the Pixma 4000.

So I recommend searching the forum for newer and more gentle methods of unclogging. I think your idea of backflushing by drawing fluid backwards sounds reasonable. By pushing liquid through the printhead in the normal direction I think you risk moving the clog from the passage to the nozzles. You could place the print head in a shallow tray with a few millimetres of Windex and try to suck up the Windex through the magenta ink inlet. But before doing anything to the printhead, I think it is better to search the forum and see what has worked for others.

 

[panos]

This cleaning method has been used by many with success. It's best to do it with paper towels instead of tissue.

Keep repeating the steps until you see clean fluid appearing on all the pickup disks. If it doesn't after 3-4 repetitions, then you can switch to a more intensive method.

 

[ThrillaMozilla]

It might take me a few days or weeks to figure this out because I'm not printing a lot at the moment. But at least I understand it better now. Thanks very much, guys.

 

[ThrillaMozilla]

I won't know for sure until I've done some more printing (and I don't have much printing to do now), but it appears to have been the cartridges. I'll post more when it's definite.

I notice that when you pull out a well-working cartridge and suck a little ink out (or blow through the vent), you get ink, not foam or air. With the problem cartridge, I noticed that when I blew hard into the vent, or sucked on the cartridge with a syringe, I got nothing unless I drew the syringe back fairly hard and rapidly. This cartridge is partly transparent, and I could see that there was lots of ink in the ink chamber. So either the sponge was empty, or air was bypassing the sponge. With a stronger vacuum I got ink, which I think was coming from the ink chamber.

I think I know the cause of the problem, and it's kind of interesting. I'll be forthcoming as soon as I get definitive information. Meanwhile, remember that some of you all have those transparent cartridges that are so revealing, and you print as much in a day than I do in a year.