Probably 'done and dusted' by now but here goes... should it be the print head, yes there are times a new printhead will resolve an issue and others sadly, a faulty head will take the digi-board with it.
Another problem is to remove the print head is to cleaned the contacts with a clean soft...
Yep spot on Hat, the ip8750 is a different beast, it's got a mud guard kinda thing never ever had to clean it once, just looked now and it's all nice and clean the rollers are well protected and like you say the ink isn't squirted all over the place like the ip5000 series, which often required...
"Hey, there's a pin thingy just fell out, werzit go"?
Must admit I didn't have ALL the services running worked a treat for me, no viruses, no hacks AND that was 32bits, gone all posh now I'm on Win 7 64bits.
Ah my bad sorry, I should have explained....you have to remove the actual print head assembly cradle which is released by lifting a lever on the right hand side of the ink tanks after removing the ink tanks, this is the usual thing in many Canon printers.
To get 'no print head installed' is...
No don't laugh...... I just semi retired my XP pro 'pewter' and built a Win 7 one, still gonna install XP on a spare drive though.
Trouble is with Win 10 there's a lot of configging to do otherwise it'll be phoning home letting Billy Gate's know what you are up to.... and no doubt other...
It's not just Canon is it? They're all at it.... they put less and less in their ink tank then they lower the 'squirt count'.
Dunno about Canon, but doesn't Epson leave about 20% ink tank full when empty? Just can't work this out Canon boils the ink and we know what happens to a kettle...
What about the contacts between the head housing assembly and the print head? Sometimes they get covered in ink or contaminated and this will give 'head not installed' error, also check the contact springs have not been accidentally bent. Use a slightly moist lint free cloth to wipe the gold...
The 5B00 error can occur if one of the ink tanks are not seated properly.
Edit:
See Canon link
http://community.usa.canon.com/t5/Personal-Printers/Pixma-mg6220/td-p/6415
Dave
Anyone caught out like I was with No CD print on a Canon ip8750.... you get error, 'A printer supporting paper is not installed' when printing a CD and you can not get past the 'Printer set button' to the actual 'print' button to print your design.
Check your version mine was Easy Photo Print...
How about printing a test page from the printers GUI?
You said you unpowered..... could I ask was this the printer, did you leave it unpowered for about 5 minutes to be sure? If not I would give it a try.
I guess the internal ram isn't being erased... you sent a piccy to the printer and it's...
How about a complete power down for two or three minutes, disconnecting the main power cord and try again to cause a reboot - me thinking it could be a glitch due to some spike on the mains.
Cost now't to try.... just a thought.
I had a IP4950 that printed broad zag zag patterns, the cure was...
'One of these days I am going to do a series, capturing the reaction of the tourists.'
That would be interesting and fun, you are bound get some good shot's, a matter of being in the right place at the right time I guess.... and waiting.
I don't know much about EMU's, to me they seem more...
A black swan on the farm next door to my favorite watering hole, Foresters Arms at Glazebury, they also have a Emu, I just got the camera out of the way before it snapped at the lens - it looked docile, it looked friendly but it's a 'snapper' I will keep at a distance in future.
Taken with a...
The Leeds Liverpool Bridgewater canal at Leigh town center, Gtr Manchester.
Imagine, if I've had had a pint or two anything could have happened. I had to crop the jpeg to upload it. Its one of them pictures that looks confusing when looking at arms length.
The camera is a Canon A650IS, I...
I dunno if it's been asked..... does it squeel all of the time during printing, just the starting up process or when paper feeding?
Thought I'd clod a spanner in the works. Canon printers are known to clunk and click some louder than others.... but never squeak.
Now I'm gonna go off topic...
Seeing there was a improvement after cleaning the strip *may* yield a clue.
Could the strip be damaged or marked in anyway, also is it possible cleaning the 'opto sensor' the strip uses? This might able to be done by using a folded sheet of inject or typing paper, remembering to clean each...
Are you sure it's not the logic board? Sometimes Canon recommends changing this along with the print head.
I've got a iP4950 and getting a B200, whether I should take a gamble and just change the print head.
Canon power supplies are usually pretty reliable, what are the error codes or light...