I purchased a Vantec NS-360SU (Midnight Blue) external hard drive enclosure after receiving a Western Digital Caviar Green 1TB SATA hard drive, as my computer has IDE.
Everything was going fine until about 2 weeks ago. I've tried different FAQs and troubleshooting guides, updated my BIOS, and I have not been able to fix the problem.
I turn the device on or connect it, the computer recognizes it and after a few seconds the activity light on the front dims and then it acts like it's shut off, although it's still on and the computer hasn't signaled that it's off. If I turn it off, the it disconnects. So basically, it acts like it's disconnected while it's connected. It doesn't show up in My Computer or the Device Manager in this state. It also slows my computer down and stops a few tasks when it's "on". Sometimes it randomly works and I have no problems, but that's maybe once every few days. I've tried turning it on and off a few times, but I didn't do it too much as I'm unsure if that's good on the hardware. I don't know for sure if it's the hard drive enclosure, the hard drive itself, or my computer, which is a Gateway 300S, I think.
Sounds like it might be a failure with the power adapter for the external enclosure. Are you sure your PC only has IDE? Almost all PCs built after 2003 have S-ATA ports inside, even if they don't have S-ATA power connections (you can buy cheap adapters for this).