Agree Farmer, but having just bought a 7900 this thread scares the crap out of me. :]
I can understand your concern. I Bought my 9890 last August. At the time, 750 for an extended warranty seemed an awful lot. I've had a 4000, and still have my 3800 and 7800. They all work flawlessly. I did buy extended warranties for the 4000, but never had cause to use it. I was actually considering foregoing the cost, but this thread really give me pause. However, my Yellow and LLK have been .... misbehaving. No other channel drops out like these, and no other channel has ever needed more than a single paired cleaning.
Now, I did buy my 9890 with my AmEx, so I do have an extra year's "coverage" (they reimburse you repair costs, or replace/refund if hopeless), but I'll have to call them to see how much of a repair is covered.
I wonder. If this is truly a wide spread known factory defect, if a class action suit would not be in order?
@Alexandra
Did the 7900/9900 printers get a firmware update recently? When I was talking with the tech over my issues just the other week, I was told that one of the recent firmware updates provided paired power cleaning along with better cartridge recognition fixes.
However, from what I've read of your experiences, you have what I think is called ink starvation. In other words, you don't have a clog, just no ink at the nozzle! These printer have a complicated pressurized system to get ink to the head. They need that to keep up with the speed at which it prints. If you have a pressurization issue, or air leak in your LLK channel, then you will never have ink at the head. And the way you described it gradually getting worse the more you used it, really leads me to think you need to see if you can replace the damper, and check the line connections. This is easy to do on a 4000/x800 series. No idea on the new x900 though.
Hope you get your machine up and running. What a nightmare, for sure!