Missing color in printouts of Canon Multipass F80 printer

I have a canon Multipass F80 which is at least 6 years old and it still works great,

way to go canon!! However, over the past couple months I noticed that color printouts were missing one color, magenta. Yet the ink cartridge for magenta was full. I did some swapping of cartridges and some deep cleaning using the Printer Properties dialog but nothing would help. I must have done a least a dozen deep cleanings with no improvement.

I opened up the printhead mechanism as it was clearly designed for that purpose. The printhead can then be pulled out for repair.

I tried rinsing the printhead, that didn’t help. I tried putting a large straw over the magenta intake  (where the ink goes from cartridge into printhead) and blowing so as to force the water through but that didn’t work either. I noticed after that, when drying the printhead, some yellow and cyan ink was on the paper towel, but no magenta.

After a lot of reading on the web, I came to the conclusion that soaking the printhead in windex might work. And it did!! I put the printhead in a clean, empty yogourt container and added Windex until the ink parts were submerged, left it overnight, and next evening when I pulled it out it looked super clean (the liquid in the container was full of ink). I dried it and this time, there was magenta on the paper towel, so something had changed. Once I put the printhead back in the printer, one printout showed it worked better than new. Hurray, just saved us a few hundred dollars.

The Canon Multipass F80 is a great printer, I hope it works for a long time!