Mr
@The Hat thank You.
I will be very carfull with this printer for I read this whole thread and You mentioned that this is a inteligent printer (whatever this may be).
I have run one cleaning cycle for all 3 units, than two cleaning cycles for unit nr 3 (because only red waas missing), and one deep cleaning for unit 3, after every cycle I ran a nozzle check to see what the results are.
Then I let it sit for around 18 to 20 hours and did a nozzle check and a cleaning cycle (normal) to unit 3. In the meantime I had to replace 2 inks with new ones (R and MBK) - it is terrifying how fast cleaning seems to consume (the no so cheap) ink.
The printer was disconnected from power for probably one hour, because I wanted to get the printing head carriage into the middle in order to put a paper towel underneath it, that is soaked with printer cleaning solution to soften potential cloggs, but since I could not get the carriage to move I plugged the printer into power supply and gave up the idea with the paper towel.
I looked with a flashlight into the printer and all ink "tubes" are filled with ink, I could see no air in them - I had this with my Epson Stylus Pro 4800, which caused sometimes colors to go missing.
As for turning the printer on or of, I only use the power on button, no pulling out the power supply, because I have the feeling that druing startup and shutdown the printer pumps ink "around", and it would be unwise to disrupt this process by unplugging power.
Maybe worth to mention, that before all of this, my wife got (she is the one who prints photos) an error (I don't remember the number) that said to unplug the printer from power supply and hand it over to Canon service, after that I started the cleaning cycles and the error didn't show up again.
I have removed all cartriges to give them a good shaking and reinstalled them and run a nozzle check. The outcome was the same as before, unit 1 and 2 fine in unit 3 MBK, R and CO missing.
I took them out again and weighed them (on a kitchen scale) and an full cartridge is 73 g, while an empty is 36 g (I have not original inks - the one I have are from printklex in Hamburg, Germany), this is what I got:
unit 1: GY = 59 g, PBK = 68 g, LGY = 54 g, DGY = 47 g,
unit 2: PC = 54 g, M = 58 g, Y = 63 g, PM = 51 g,
unit 3: MBK = 71 g, C = 47 g, R = 72 g, CO = 58 g.
So to me it seems that ther is ink in them.
Now my wife printed between the cleaning cycles 3 small photos (10 x 15 cm) and it looks like red is missing, but beside this, they look quite ok to me.
Any suggestions what I might do?
Thanks.
Wojtek
P.S.: I know that the way to success with bringing a printer back to life is patience and Mr. The Hat's advice ;-) .