Canon ip4300 nozzle check changed, but printer seems OK

[IanYY]

This is what the CLI-8 BK (Dye Photo Black) line used to look like on my ip4300 nozzle check (Oct 2009) ...
Scanned image

This is what it looks like now (Dec 2009) ...

It's fainter in the top half, but there's no indication of any nozzles missing. The rest of the nozzle check is perfect and unchanged from what it used to be.

The second test was soon after installing Windows 7 (64-bit) on the PC, so I thought the latest Win7 driver might have changed the nozzle check (I don't run enough nozzle checks to be sure it changed exactly when Win7 was installed). So I attached the printer to an old Windows 98 PC and the lighter band was still present. I think this rules out Windows 7, unless the new driver also stored something remembered in the printer's firmware.

I printed off some photos and can't see any problems with them, but my photos don't use much photo black so it's not a convincing test. If it weren't for the fact that the nozzle check is different from what it used to be, I wouldn't be aware of any problem.

I removed the print head, soaked a small amount of ink flush through the nozzles, ran a deep clean, ran the manual print head adjustment routine - no difference whatsoever. I am using original Canon cartridges, refilled with HobbiColors ink.

Is this normal? Should I be worried? Anything else I can do?
Ian

 

[pharmacist]

It looks like an electrical problem. Did you try to produce a solid black column and try to print this using photo paper setting to foce the usage of dye black ink ? If you get alternating lighter/darker bands you can isolate your problem.

Try to take out the printhead and carefully clean the gold-plated contacts on both the printhead and the craddle it sits on.

 

[IanYY]

OK, pharmacist, I printed a 40mm square in 100% black on "Glossy Photo Paper", "Standard Colour Intensity". Then scanned the image, shown below. Before the ink was fully dry, it was possible to see some banding where the ink had been laid down. But after a minute all banding had disappeared and the square was a perfect black. The "wet ink" banding was very narrow and did not correspond to the wide band shown in the nozzle check.

Scanned image (perfect) ...
White spots & marks are from the scanner, not the printed image

This seems more of a puzzle than a problem - but I'm still looking for an answer.
Ian

 

[ghwellsjr]

Pharmacist's first advice is correct. You have an electrical problem. Your only hope is that it is a bad contact on the back of the cartridge. If you cannot fix it by cleaning the contacts then it cannot be fixed. You will need a new print head to fix the problem. Don't try cleaning the print head outside of the printer or you may damage it which may damage your printer.

When you do photo printing, the printer always overlaps the scans of the print head so you cannot see any problem when printing out a block of solid black. The nozzle check is the only way to see that you have a problem. Of course, if you cannot see the problem when printing photos on photo paper, then maybe you can live with the problem.

 

[IanYY]

My first thought was that this was software, but I will now concede that there really is a fault.

This section of a "Service Test Print" clearly shows photo-black is not firing on all cylinders ...

I have been reading your (ghwellsjr) 2006 analysis of print heads - http://www.nifty-stuff.com/forum/viewtopic.php?id=1504 - which describes the photo-black nozzles as being in two columns with 128 nozzles in each column (may be slightly different for an ip4300). So it looks like the top half of the nozzles on one side are not firing.

It's possible they could all be blocked, but it seems an unlikely coincidence that 64 (or so) adjacent nozzles should all be blocked at the same time.

Not firing could be caused by:
1. An electrical fault (bad/broken contacts/wires) as suggested, or
2. Burnt out nozzles.

There is no reason for the nozzles to be burnt out - the photo-black cartridge has never run dry or shown any previous problems with ink flow - but it's possible.

Anyway, I've now cleaned the printhead contacts, had another go at flushing the print head's black channel, and done another deep clean. All to no effect.

But I have to repeat that I have yet to see any document or photo showing any faults. So I will do nothing more until the printer actually starts to cause me real problems.

Thanks for your help.
Ian

 

[IanYY]

The 100% black test (see post #3 above) wasn't a good test. It's true the fault doesn't show on 100% black, but it does show on greyer colours - this image is 100%, 50%, 75% and 25% black ...

You have to look hard to see the faults in the screen image, but on the original the banding is clearly visible in the 50% section, and less so in the 75% and 25% sections. The horizontal dark lines are at 2mm intervals (scaling will make it look a little different on screen) and can't be removed by print-head alignment (I've tried several times).

It still only a minor fault and a new print-head seems an excessive luxury, but it seems the only answer.
Ian

 

[ghwellsjr]

I'm sure you have already checked to see if the printer is still under warranty because if it is, Canon will probably replace the print head for free. Wouldn't hurt to contact them.

 

[IanYY]

For the benefit of anyone with a similar problem, I can report that the printer now works beautifully with its new print head.

Looking forward to at least another 3 years trouble-free printing - but, just in case, I've cleaned the old print head and kept it, so next time a quick swap will prove whether a fault is a head fault or a logic board fault.

Ian

 

[ghwellsjr]

That's a good idea. Keeping a defective print head that you know will not burn out your printer is the best way to determine if a future problem can be corrected by purchasing another print head.

And I'm glad to hear of your success.