Damn, don't throw it away. I wish I could drive down to Arkansas from Atlanta. I could use it for parts if nothing else! Almost certainly it is the Hitachi hard drive that is located on the logic board. I've been there as have many of us. You can replace that part yourself easily. I had mine replaced by the tech and it took him 10 minutes. He just popped it in. I wish I had watched him closer now. I went in the kitchen for some coffee, came out and it was done. A manual is available for the Z on that wiki.
These hard drives are known to fail. Personally I think Hitachi quality control has gotten bad, at least on these that HP used. I had to have a new Hitachi that I put in my in my Mac replaced after 6 months. The tech couldn't even remove the data it was so screwed up. Mine in the Z failed after 2 years. Some people have had two of them put in.
They pop these logic boards that control everything in and out in a few minutes too, in my case he just put both of them in without even analyzing the hard drive though he knew that was the culprit. It isn't like the main board of the Epsons that demands a lot of effort, alignment, and reprogramming to install.
Despite some of the questionable parts used in the Z series, like the belt and the hard drive, this is a printer that can be easily have the components switched out to restore the printer. Most of the other printers are gone completely after the carriage and or heads wear out.
I'm thinking about a Canon 8300 in February myself. But I will certainly want to keep the Z going for black and white if nothing else. The dmax is just wonderful. I've been doing some gorgeous prints on an uncoated natural kozo paper this week and nothing can touch it, and it even profiled right in the printer in 20 minutes without me being in the room. I wish the Canon had that kind of dmax on matt media but they are more like Epson.
john