Chosen Solution
I have a 4TB Seagate expansion drive (long out of warranty) which was knocked off a table and will no longer power up. Can someone walk me through the process of removing the hdd from the expansion case and setting up an hdd reader to let me access the files?
See if this guide will help you figure out how to get the enclosure open: Seagate 5TB External USB3 Teardown
Cracking open the case won’t help you to gain access to the files as it sounds like the platters and/or heads are in trouble here. I’m assuming the case its self is not damaged (the port and power connectors are intact). At this point I think you’re going to need to ship the drive out to a recovery service if the data is still important. It won’t be cheap ;-{ Data Recovery Services Backing up is so important! I even back up the back up ;-}