I thought I'd follow up my last post on my troubled Terastation. I replaced the power supply, only to find that it still shutdown a few minutes after turning on. I finally determined that this was happening as a result of a corrupt operating system. The Terastation apparently responds to a failed bootup by turning off. I attempted several times to replace the firmware (a great opportunity to try using a telnet enabled firmware), but the device kept shutting down before the firmware update could complete.
After resolving that I didn't care about the data that was on the drives (I had already recovered it, see last post), I figured out an approach that worked. I took each drive and connected to a linux booted computer (I used a Knoppix live CD). Each time, I went into fdisk and observed that there didn't appear to be any partitions. Regardless, I created a partition (the type doesn't matter), and then deleted it - leaving no partitions again. After completing this for all 4 drives, I reassembled the Terastation and was able to execute the firmware update with no problem.
After the firmware update was complete, there was no data on the drives - but my config info was somehow intact! I was surprised, they must store it in flash or NVRAM. The only thing I had to do was reset the language to english, which involved a lot backflips and screwing around, until I found that article.
So now I have a fully functioning, blank Terastation that is telnet enabled and has the latest firmware! Exciting, now I just need to come up with a cool project for it - or more likely I will just put my data back onto it, as it's a little annoying having my desktop as the server for the house.