Which specific USB adapter. Not all will work with all drives.I'm trying to get the data off the hard drive to copy to a new computer. The adapter I'm using is a SATA/PATA/IDE Drive to USB 2.0 adapter.
OK, I have a similar one.Here's a link to the adapter
Yes, that is the typical multi headed cable arrangement with a wall plugin.Link won't open for me. So I have to make sure; If that adapter comes with external power source/cable/connectors (assuming it does because USAFRet didn't mention it need enxternal power source). Have you checked to make sure if they're connected firmly and that the 3.5" drive is getting enough power?
When you connected the drive and power it up if you touch a corner of it gently does it move/vibrate a bit? As USAFRet said earlier the drive might be dead.