Pixma ip4500 : automatic remap of defective nozzles ?

[Artur5]

Some months ago, the printhead of my ip4000 died and I wasn't unable to find any more reliable sources of QY6-0049 new units, being discontinued for some years already. Therefore I bought an used ip4500 in, according to seller words, perfect shape. Now I found out that printheads for the ip4500 have been also discontinued. Thanks a lot for your support Canon .
I said that the used ip45000 was supposedly in top shape but my first nozzle test showed that the photo black was defective. 25% of the nozzles were dead in a perfect rectangular pattern. So it weren't clogs but electrical damage. I contacted the seller and they told me how sorry they were for this and that they hadn't detected the problem at all but, being the printer used and sold at a discounted price, I couldn't expect 100% functionality. It wasn't an Ebay sale but a secondhand site of rather shady reputation, so I wasn't that surprised but I couldn't do anything more than tell them, in unkind words, what I thought of their message.
Anyway, my surprise was that everything I printed, apart from nozzle tests, seemed to came perfectly: no streaks, banding or anything in spite of 25% dead nozzles. I expect then that the printer must do an automatic remapping when detects any electrical failure. With common clogs the printer of course wouldn't know about it, but being an electrical issue I guess that it does. In fact it refuses to automatic printhead alignments, saying that there's some problem with the printhead.
Bad news is that, yesterday, an extended nozzle test showed that another 25% of the photoblack nozzles are dead, making it a total of 50% of casualties but, again, it doesn't shows at all when I print photos or graphics. Not a single defect to be seen, whether on plain, high resolution or photo paper.
My take on this is that I must buy a new printhead before 100% of the photoblack nozzles die. Of course, the remaining new ip4500 printheads for sale seem to have skyrocketed in price on ebay and everywhere else,
BTW Do you folks, know of any reliable source that still has QY6-0075 printheads in stock and ships to Europe ?,

 

[palombian]

You probably printed documents on plain paper, this doesn't use the photo black but the big pigment black cartridge.

The bad news: if you continue to print (even without photo black) the printer will soon die.

The good news: if you are handy you can mask the electrical contacts of the photo black nozzles on the printhead, avoiding - or at least postponing - the death. But the printer will be limited to text printing, no photos.

There are specialist on the forum who maybe could help you on this.

PS: new printers are not that expensive (and can be refilled too).

Correction: I once had this on my PRO9500, 50% of the cyan nozzles printed lighter (indicating an electric problem on that part of the nozzles), it was not seen on the photos but 2 weeks later the printhead died.
This could suggest a remapping, but I do not understand why Canon should do this effort if it doesn't last long.

 

[martin0reg]

....Of course, the remaining new ip4500 printheads for sale seem to have skyrocketed in price on ebay and everywhere else,
BTW Do you folks, know of any reliable source that still has QY6-0075 printheads in stock and ships to Europe ?,

I seem to have exactly the same problem.
Just bought 2 qy6-0049 (ip4000) on aliexpress, knowing that these have to be refurbished ones ... although many of them are offered as "100% new original".
Only a few sellers are telling the truth and offer as what they are: refurbished.
So I bought these two and one printed a decent nozzle check. After disputing with the seller, attaching photos of nozzle checks (or non-original package) I got partial refund for the really bad one and kept the better one.
These are offered for under 50 €
The price of qy6-0075 on aliexpress is higher, similar to what new ones had cost until they were out of production, around 70 €... but they are NOT new, only refurbished - and so getting a fully working is a matter of luck..

Regarding "remapping": I have read about it and I guess this would explain the much higher amount of nozzles compared to epson piezo heads - while printing with similar resolution. My understanding is that thermal heads may have this "surplus" of nozzles for substituting the inevitably burnt out nozzles.

 

[turbguy]

As far as I know, only truly PROFESSIONAL Canon Printers (the BIG ones that can handle wide rolls, and come with legs) remap nozzles. To remap nozzles, the printer must determine/detect which ones are not firing, which is a lot more hardware required. Yes, the printhead "could" report nozzle addresses that have an "open" thermal heater, requiring two-way communication between printhead and firmware. That's giving residential desktop printers a LOT of credit...

Regarding nozzle count, it only takes ONE nozzle of each color to successfully print...it just takes a LOT longer to print across the length of the page as the paper increments very small amounts.

Regarding the refusal to perform auto-alignment functions, what does the manual alignment option produce??

 

[The Hat]

Regarding the refusal to perform auto-alignment functions, what does the manual alignment option produce??

I reckon a far better alignment in every respect because you control the final output.

Print the previous setting before making any new adjustments.

I never use the Automatic head alignment..

 

[palombian]

As far as I know, only truly PROFESSIONAL Canon Printers (the BIG ones that can handle wide rolls, and come with legs) remap nozzles. To remap nozzles, the printer must determine/detect which ones are not firing, which is a lot more hardware required. Yes, the printhead "could" report nozzle addresses that have an "open" thermal heater, requiring two-way communication between printhead and firmware. That's giving residential desktop printers a LOT of credit...

Regarding nozzle count, it only takes ONE nozzle of each color to successfully print...it just takes a LOT longer to print across the length of the page as the paper increments very small amounts.

Regarding the refusal to perform auto-alignment functions, what does the manual alignment option produce??

It produces a number of patterns where you have to choose the best.
I never understood how the printer could "see" this itself to adjust automatically.

But IMO this has to do with the timing of the printhead movement and nozzle firing, not with nozzle remapping.

 

[PeterBJ]

It produces a number of patterns where you have to choose the best.
I never understood how the printer could "see" this itself to adjust automatically.

A photo sensor on the underside of the print head carriage checks the printed patches for unevenness. You choose the least striped patch when doing a manual print head alignment, the sensor does something similar when an automatic alignment is done.