Canon MP780 only prints black - have cleaned printhead - what else?

[lakanook]

Hi!

My Canon MP780 had some streaks in all colors expect the black 3eBK, and after a little while, the colors stopped printing altogether. I did several cleaning/deep cleaning/printhead refreshing, all to no avail. I then tried to clean the printhead with Windex (soak for 5 hours and dry overnight), as recommended on this site by several people. The first print of the nozzle check showed a little color, streaked as before, then I did more cleaning/deep cleaning/printhead refreshing, and since then only black prints again.

All colors: black photo, cyan, magenta and yellow, do not print AT ALL. Not even a drop of ink on the paper.

Here's a scan of my extended nozzle check and regular nozzle check at the bottom of it:

Does anyone have an idea of what else I could try?

I'm so scared of hearing "replace the printhead"... That would cost more than the printer is worth in this state, as I'm in Australia and the part has to be shipped from half-way around the world (costly shipping). Please tell me if there's anything else I could check.

Thanks!
Myriam

 

[panos]

Possibly a purge unit issue. Read this thread carefully.

 

[turbguy]

I agree it could possibly a plugged or defective purge unit. Easy to repair but REALLY hard to access if it needs service!

Wayne

 

[lakanook]

Just a quick update on this issue. I was waiting to have the time to give it a try, as when the gurus say it's a big job to reach the purge unit I thought it would probably take me the whole day...

I was still printing with it - black only - until a few days ago, when it stopped printing completely and gave me the message "WRONG CARTRIDGE" on the display.

After researching this issue, the only people I found who seemed to have resolved this problem for good are the ones who replaced the printhead. I found some printheads but they were well over $100!!! I figured this printer has too many complex problems for its worth.

I have now bought a "new" used printer instead, but when I have time I still plan on trying to dismantle this one to reach the purge unit, and/or do some testing with another printhead. I got so stressed about this printer that I am in the process of buying a total of 4 MP780's (2 apparently working and 2 for parts) so I have plenty of spare parts for the future. Yes, I was very lucky to find so many just when I needed them! I know, it's probably an overkill, but I figured I might give a try to repairing at least one of them and putting it back on ebay while keeping enough spares to have peace of mind for a while.

I'll update again once (and if!) I find the courage to pull this printer apart...