Pretty much every one of these I’ve owned has failed.
Almost all of my failed power supplies were connected to one of our otherwise awesome Other World Computing Mercury Elite-AL enclosures. Generally, the power adapters last about a year, then go hissy and fail. All of them have been plugged into power conditioning UPSes.
The model number is ACU057A-512. They’re manufactured by SunFone who also supply power adapters for LaCie. These fail so dependably, I’ve taken to keeping spares on hand to make sure I can keep our server’s backup drives online.
If you’re lucky, the power supply will just fail and the drive will no longer mount. If you’re unlucky, the power supply will gradually fail and some data on the drive will be corrupted. Often the drives will be heard faintly clicking, and if they mount at all, they’ll report all sorts of errors. After at least 8-10 failures, I can only remember one instance where data was compromised. Thankfully that drive was part of a redundant backup strategy, so nothing was lost.
When these fail, they emit a hissing sound. Sometimes it can be heard from across a noisy room, other times I had to hold the brick up to my ear. Sounds like this:
Bob Friesenhahn’s report on MacFixit also mirrors my experience.
I have four D-series LaCie drives here. All of them have experienced power failure. In fact, in the past couple of years I have replaced six failed power supplies. The power supply model number is ACU057A-0512.
The failed supplies were all plugged into a high grade UPS and see an average temperature of 75 degrees. Average time to fail seems to be six months. No supply has lasted more than one year.
Now I purchase these supplies in bulk and keep three of them on hand at all times.
As of September 2009, it looks like OWC has finally switched to a completely different power adapter. Also, a their replacement part number for the doomed SunFone adapters now shows Jentec model JTA0707-Y. OWC has been really good to me over the years, so I’m hoping this change will be the end of this story.
Update January 2011: All of the replacement Jentec power supplies have been working smoothly for over a year.