white stripes on Canon MX700, replace print head or circuitry problem?

[inoe]

I have PIXMA MX700 for over a year now. The last couple of days it has stripes on color printout, but full B/W text (and faxes) printed ok.

I have done head cleaning, deep head cleaning, manual head cleaning, no improvement.

The nozzle check pattern is as below:



White horizontal stripes of about 3mm alternating with printed images (also about 3 mm).

The white stripes are well defined and tidy (not degrading like inks running out gradually).

This printer is attached to home network, and I have printed from multiple PC and laptops with similar result.

All cartridges have adequate amount of ink in reserve. All CANON original (because i don't use the printer so much, so the the difference between buying original and aftermarket inks for my purpose is negligible).

I have tried various methods of nozzle cleaning, deep nozzle cleaning both from printer maintenance menu and manual print head cleaning. No improvement whatsoever.

I don't like the idea of buying new printhead only to found out the the problem is actually in the printer main circuitry, and I ended up with a perfectly functional spare, and a broken printer which will likely be tossed out anyway (service support in my area is virtually nonexistent).

Any help will be appreciated.

Thanks.

inoe

 

[ghwellsjr]

This is, as I think you have concluded, an electrical problem. Sometimes, this type of problem can fixed by removing the cartridges and then the print head and cleaning the gold contacts on the back of the print head and making sure there is no problem with the contacts sticking out of the carriage. Otherwise, a new print head almost aways fixes the problem. I have never heard of this type of electrical problem being in the printer instead of just in the print head.

 

[inoe]

ghwellsjr,

many thanks for the reply.

If it really is the print head that causes this, i guess it's a good news.

However, i wanted to be absolutely sure that it is the print head (you said that replacing the print head almost always fixed this type of problem).

Is there a procedure or method or test to conclusively determine that it is the print head that causes this (or circuitry within the print head unit), and not the printer logic board or other circuitry within the printer unit?

Thanks a lot.

inoe

 

[ghwellsjr]

I don't know of any case where this type of print head problem wasn't fixed by getting a new print head but I don't like to state that it will always fix the problem because yours could be the first and I wouldn't want you to be unaware of the potential risk.

What country are you located in?

 

[inoe]

ghwellsjr, thanks for responding so quickly.

So, you are sure that the nozzle check pattern indicates almost conclusively indicate print head problem instead of other components/circuitry on the printer?

I understand that you cannot guarantee that it will fixed my problem, and I certainly shouldn't expect that. However, since you have been very helpful and knowledgeable in this forum, maybe you have a way or a test that I could perform to determine that it is indeed a print head problem, and to hopefully ruled out other circuitry problem conclusively.

Could a erratic power or electrical spike caused a malfunction in the logic board which caused this symptom?

I live in Indonesia, 2 islands and over 1000 miles away from the capital, where all service center is located. This is also why I also suspect a bad electrical may do something to the internal of the printer (the printer power is supplied from the UPS/voltage regulator, which is running fine). Our power grid quality is unreliable and pathetic.

I guess what i am asking is whether purchasing a new print head (can be ordered and air mailed from Jakarta, will arrived in 2 - 3 days) would be the best course of action.

I apologize if i came across as too persistent and pushy, it was not my intention.

Thanks a million,
inoe

 

[ghwellsjr]

You're doing fine, I understand.

I don't think this problem was caused by erratic power, it happens at random in printers that were behaving normally. I'm sure if you could take the printer to a service center, they would just try a new print head (or maybe they have a spare that they use for this purpose) to determine if that is the problem and the solution.

Let me put it this way: if it were my printer, I wouldn't hesitate to put in a new print head and, in fact, I have done this many times and it has always fixed the problem.

 

[inoe]

Thanks. I think i agree with you.

Ordering new print head now.

Thanks a lot.

inoe

 

[inoe]

Update:

Just have a phone conversation with service technician of Canon Jakarta. After describing the symptoms and the nozzle check result, he advised me to hold on ordering new print head, he said that there are three possibilities for the symptoms:
1. ink cartridge, which was immediately ruled out.
2. print head.
3. ink (?) pump on the main unit.

I am still leaning toward print head failure. My question is, judging on the nozzle check pattern, could that indicates pump failure? I mean, all 4 inks delivered fairly consistently, except for the stripes. Can we safely discounted pump failure?

The technician only have my verbal description of the nozzle check pattern (he does not feel that he need to see the nozzle check pattern, which i offered to send to him by e-mail). Yet he is fairly confident that he got a clear idea what the nozzle check pattern looks like, and that he insisted to check for pump failure before ordering the new print head.

The problem of course, is that it would take weeks to send the unit to Jakarta, while ordering print head would only took 2 - 3 days. The technician said that to rule out the pump, the first thing that they will do is replacing the print head, and see if that fixes the problem. Catch-22.

Please comment.

Thanks,
inoe

 

[ghwellsjr]

He's right, without seeing the nozzle check, but you can check the purge pump by doing this (post #2). If you don't have Windex or some other liquid window cleaner, just use water. It won't take long and you can at least assure yourself that the purge pump is working. But even if it isn't, and you fix it, you still have a print head problem.

 

[inoe]

Thanks.

As a matter of fact, I already read and performed the test that you referred to back when I did manual head cleaning etc., and the windex sucked clear from both pads at the first go.

Interestingly, you referring to a pump on the purge system clarified things for me.

From the canon tech explanation, I was under the (false?) impression that there is a delivery pump/pumps on the main body unit that squirts ink from nozzles, and white stripes may be caused by a failure of such pump/s.

I was confused, because there should not be a pump at that stage, and even if there is (highly doubtful), it has to be on the print head, where the nozzles strips are. The only connection between the body and the print head are the array of electrical contacts. If there is indeed an ink delivery pump in the body unit separated from the print head, it will also require some sort of pneumatic/pressurized tubes/pipes to the print head where the ink and the nozzles are, right?

And as far as I can remember, canon bublejet tech uses resistive-heating-&-bubble-forming-microtubes as the method of ink delivery, it should not involved any pump.

Now my question is, how many pumps are there on the printer body unit? are there more pumps other than the purge pump that you mentioned (which we know from the purge test above is likely to be OK)?

Regards,
inoe