I have a Canon MP 560 which is still chugging along after 15 years. I've had to nurse it a few times by cleaning the head etc and one time had a bigger problem which I can't recall exactly. For that problem I got help from an online forum called fixyourownprinter.com. But I've just tried to go to it and it doesn't seem to exist any longer beyond a facebook page with a last post from 2009.....
But , in my contacts is the email address of the individual who helped me a lot.....Bud Stansbury at bud4golf@att.net. The last communication we had was in 2014 so I have no idea if the email address is still good or if he is still helping people.
Without a doubt my printer will now go completely tits up......
