About a year ago, I had a Yamaha CRW-F1 drive go bad on me with Power Calibration errors after about 6 months of operation. One thing I noticed when I examined the drive tray was that there was a fine coating of dust all over everything, making the tray look a lighter shade of grayish-black than it normally does. There was enough dust that I could rub my finger over it and pick up a small white spot on my finger, and leave a trail on the tray.
I'm assuming this dust was sucked in due to negative air pressure inside my computer case. All drives have this problem to some degree but most drives I've seen have a gasket or some other type of seal around the tray. The Yamaha doesn't seem to be sealed at all.
Anyway, I got the drive fixed under warranty and it is working fine now, but I put it in an external Firewire chassis to be safe, since I can leave it turned off most of the time when the computer is running. I also have a second CRW-F1 which I bought to use while the first one was out for repair, and it also exhibited the dust entry problem after only a couple of months (and I don't even leave my PC on all the time). That drive did not fail on me (it is now stored away as a spare) so I'm wondering whether the dust was the cause of my original problem or not.
The reason I ask is that I want to use the external chassis for something else, so I want to put the drive back in my computer case. But I'm worried about dust killing it again.
So I'm wondering if others have seen the kind of dust buildup I'm talking about, and whether it has caused any problems for you? It's easy to miss because the "black" tray is somewhat grayish to begin with, and the change in color is very gradual. I am operating in a somewhat dusty home environment, but I've never seen this kind of problem on any internal drive before.