QY6-0067 diagnosis

[sneezer2]

@Technician
Sorry, but I do not comprehend this repeated emphasis on my imputed desire to repair or even to find out what is wrong with
this printhead. I have said repeatedly and repeatedly that this is NOT the case. Due to a number of very
astute posts by various members, I think:

1) It is beyond very much doubt that we DO know what is wrong with it.
2) That there is no question of it being repaired or rejuvenated.
3) That there remain lots of questions about what happens in the rest
of the circuitry when a printhead does go bad and even before that.
4) That some of the apparent "damage" consequent on continued use of
a defective printhead or continued use of a "damaged" logic board,
may not be real damage at all.
5) That the modes of possible further damage are poorly understood.

It is my very speculative approach:

1) That it may be possible to reverse or avoid some instances of apparent
"damage" (there appear to be actual examples).
2) That it would be very good if we could discern between real damage
and erroneous indications thereof.
3) That a better understanding of the events and signals involved might
help with interpretation of outward indications that could sometimes
be misleading.
4) That there may be simple measurements (that we don't know about yet)
which could lead to better conclusions and less expense.

I do not think that Canon will help with this. Their recent encouragement on
the idea of routinely (and thoughtlessly) replacing printhead and logic board
together is prety insidious. Good for them and their bottom line. Bad for us
and bad for sensible use of resources.

 

[The Hat]

On the other hand, "fatal error" still seems poorly defined. @TheHat (above) seems to have "recovered" a logic board by putting in a
new printhead. Presumably, he means that it was "fatal errored" although he doesn't explicitly say so.

No, what I said was I managed to recover a print head that had been declared damaged with a B200 error and not the logic board, it ran good for another couple of months..

As we can never know what’s going on inside a print head, that’s for sure, and even when we take the whole thing apart, we will still be none the wiser for it, and it will always have to remain one of those unknowns.

When you send a printer back for repair under warrantee, the service agents will change both the logic board and printhead together, even they with all their technology, wiring diagrams and manuals wouldn’t risk further damage by only changing one of the components.

There are two types of print head errors, one which suffered electrical damage, as yours is showing, and another which is a software error issue, they can sometimes be overcome, with a bit of luck...

 

[Technician]

Mmmn...I seem to be missing something here so apologies if that's the case. In your first post you wrote that you had just purchased this printer and that it appears to be approaching five years old and not working correctly.
Now it seems to me your best course of action would be to return it to whoever sold it to you and get a full refund, at the end of the day they (the seller) have your cash and you have a duff piece of equipment. I suspect they (whoever they are) are having a chuckle at your expense, why put up with that...return it. Unless you have aspirations of becoming a printer service engineer of course.

 

[turbguy]

The most common "fatal error" is the frequent situation where a failure causes the printer to not even power up! It is common for some diagnostics on the main board to to prevent an "All-OK" signal being sent to the power supply to fully power up (without removing the print head or some other trick)...

 

[sneezer2]

@TheHat
This is what I read:
"I also have reset the logic board EPROM chip"
Sorry if I misunderstood. You did say after that, that the result was an old printhead you could use for a while longer.
I took that to mean that there had been a fatal error and that you had cleared it by inserting a new printhead.

So am I correct in re-interpreting that a fatal error could not be cleared in this way but your other error could?

I'm unfamiliar with the B200 error code, never having seen one myself. So, I've looked it up and find it doesn't really
tell you very much except that something is wrong. Some folks think that it is mostly caused by printhead problems
and many say plainly that it is overheat. Not much help there.

Your point about sending a printer back is plain enough, even to me but I would add that, even under warranty,
this is advantageous to them because of overhead cost and the low cost (to them) of these parts. If you were
to pay for it, then it would be really advantageous to them. Technology is not their only motivation.

And I hope you will forgive me for saying this but in a 35+ year career of maintaining and repairing numerous
varieties of marine electronic equipment, there were many, many occasions when factory technicians came
on board and then left without accomplishing anything. They got paid though. And I can't even count the times
when by engaging in just this kind of speculation, I was able to isolate the fault and effect a permanent fix
after they were gone.

Your points are well taken though.

 

[sneezer2]

@Technician
I got it off Craigslist from a young couple who represented it as a "working printer",
which in fact it actually is except for this chip fault which I don't expect they would
have noticed. You can see in my first post what it was and still is doing (if I plug it in).
They might have thought the print quality not perfect but it was dirt cheap, I knew
my risks and I have stated a couple of times my willingness to junk it if I have to.
If it were a commercial transaction at full price I would be upset and want to do all
the things you mention and more but it is not that. I expect no recourse. If I can learn
something from it and/or as a long shot have it in the end as a "working printer"
then I am well satisfied and not worried about the "social" aspects

 

[sneezer2]

@turbguy
Just for the sake of clarity could you stipulate your idea of just what a "fatal error" is?
Yes, I see what you just said about the power supply and have seen that in some other
posts and other threads. But is this a technical term with a precise meaning or is it
much more casual. Does a printer ever communicate this error in flashing lights
or LCD readout, or is it just dead?

 

[turbguy]

I cannot elucidate on a "fatal" error..except for a "failure to power up" (and a new print head did NOT resolve it, (Canon i9900).

I think it's "casual", not indicated with any error "readout", but others can chime in.

 

[sneezer2]

Before this thread drifts to a close, could a few of you respond to one question?

Regarding the often seen warnings about a bad print head causing damage to a logic board
(warnings which I do not discount):

What sort of voltages, currents, signals or any other conditions can you visualize or imagine
to come from a printhead that could cause damage to a logic board? By damage,
I mean actual physical damage rather than any error condition or software problem, however
severe. Damage, such as a ruined chip or other component that will no longer function
under any circumstances.

I don't believe there aren't any but I can't imagine what any of them would be.

 

[The Hat]

To answer you question properly there are many things that can cause a fatal error, if the EPROM chip gets confused by the data coming back from the print head, then you get a fatal error, and this can only be overcome with a new print head, the most common fatal error is the B200 error. (Specifically means whatever) it’s very convenient for the manufactures dough.

When a user has problems with print quality, and doesn’t know how to cure them, they usually wash/rinse the print head in some sort of liquid and then without drying the head thoroughly, puts it back into the printer.

When the printer is powered on this will blow the shit out of most if not all the nozzles and some components on the logic board too, it can also manifest itself by the printer refusing to power on at all, instant blowout of serious components. (Dead printer & print head)

Worse is still to come, the user then buys a new print head and installs that, which in turn gets blown to hell by the now damaged logic board, the user usually does not accept what’s happened and finds another printer to test out his new print head on, and it in turn then damages the logic board in that printer and so on, and so on...

To answer the other question, yes, the printer will show alternative flashing LED lights to give a general indication what and where the problems might be, its not always very specific dough. (Guesstimating...)

I have tested out many ideas on the Canon printers, and have learned one thing, you simply can’t win, you must learn to compromise and be happy to keep on refilling the carts and getting your own back on them...

P.S. they just don’t want you servicing your own printer, and you must also remember they own the software that controls YOUR printer...