Thanks for the informative comments, appreciated. I would like to respond to a few of them.
As previously stated my 8300 has served me well, but not without a significant amount of repairs though nowhere near as troubling as the LF Epson's I've owned in the past. The 8300 is my 3rd LF printer, the two previous were Epson's, both RIP at the local landfill. Please understand having changed the print heads in my 8300 perhaps close to a dozen times I am not freaking out. Heck in the first year or two both print heads were changed at least twice each. Canon claimed 5 years and I was lucky if I got 5-6 months on each of them. Rumor was that Canon had batches of the heads made in China but after so many replacements and after the earthquake brought manufacturing back to Japan. I believe but cannot prove the same situation also exist for the printers themselves. IOW's its my understanding these new printers are made in Japan, and are made and designed to a much higher standard than even the 8300/8400's.
Understand too I am NOT interested in the 8400, only 4100 assuming I don't repair my 8300. What concerns me about this head replacement this time are the error codes that have nothing to do with clogged heads. For all I know the real issue might be something on the printer itself not recognizing the head. Yes I have performed dozens of nozzle checks, that is NOT the issue. Even the Canon CS rep told me a perfectly performing head might create such errors. But do we know its the head or the printers other circuit boards?
What troubles me about the deeply discounted printer heads in your link is we don't know where they were made? Or more accurately I don't know. I would rather pay a higher price for one I know was made in Japan given my previous experience with the ones manufactured in China. FWIW I have successfully installed used heads in the past with no issues. Taken another step on more than one occasion I have taken the printer head out, manually cleaned then reinstalled with great success. One can do this via the cutter replacement command on board. I got tired of buying printer heads once or twice a year that were supposed to last 5 years. Its possible I have spent more on head replacements and the few other repairs I've done than what I paid for the printer itself.
Worth pointing out even with the numerous issues I've had with my 8300, it really has served me well much better than the Epson's. I believe Epson is a very good company I just would not ever want to own another one of their printers. On the dead desktop versions alone I could probably fill up the back of my pickup truck.
Much to consider still.
Thanks
I have one the same general age, mine is 9 years old. It runs like new so maybe I’m biased because I love the output and it’s saved me so well. I’ve had 10 large format printers and this one has by far been the most durable and trouble free of them all. Built like a tank. People seem to freak out every time the print heads need replacing. Yea they aren’t cheap. If I were in your shoes I would replace the head as these machines were built better in Japan before that horrible earthquake and simply have less issues than the IPf 8400s.
https://www.ebay.com/itm/Printhead-Print-Head-For-Canon-PF-05-IPF6300-6350-6400-8300-8310-9400-Printer/124111853556?hash=item1ce5a497f4:g:QjQAAOSwD75eZhmP
What I would do is look for a head on EBay. You can’t put a used head in so they have to be unused. I would also try Alibaba which sells a lot of print heads. I mean the most you have to loose is 2 or $300.00. It is worth the gamble and I’d much rather have one of these than the newer models. I do know when a print head starts to go bad, like maybe one channel missing, you start to get all kinds of crazy errors. It scares a lot of people and they throw them out. Did you do print a nozzle check pattern to see if nozzles are missing? That is job one. If you are missing a nozzle or it looks like it’s fading out that is the issue. If your not missing nozzles it’s something else.