To follow on to John_C21's post, see this this support page for the iP4600 or this one for the iP4920. As you can see they employed pretty much the same flash formats for the entire iP4XXX series of printers.
I love Canon printers and have used them almost exclusively for decades now. That being said, if reseating the print head doesn't fix the issue and/or cleaning and reseating the print head doesn't, either, then my advice is to get another printer.
I have purchased replacement print heads for two Canon printers in the past and one worked just fine for a while before some other hardware failure occurred, and far too soon to have made the print head purchase cost effective [they're usually more expensive as a part than a printer as a whole], and one did not work at all, suggesting that the print head failure wasn't necessarily in the print head itself but "nearby" somewhere.
Given how cheap printers have become, and how expensive printer parts are (often more than new units) they've become "disposable." As much as I hate the throw-away culture I just make sure to take a dead printer to Goodwill (or whoever may be available locally) for their computer recycling program and making sure that they know that it's not functional or suitable for resale (except for parts).
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1803, Build 17134
In a modern society where everyone thinks their opinion deserves to be heard nothing annoys me more than individuals who mistake their personal preferences for fact.
~ Commenter TheCruyffGurn on the The Guardian website, 8/13/2014