Don't throw your non-working external hard drives away!
I really hope for your sake that you keep those drives and don't bin the non-workers. Why do I say that? Well, believe it or not, around 99 times out of 100 it is not the drive that's failed but the casing it comes in. Or, rather, the electronics within the casing. If, when you plug the external drive into your computer via the USB port, it does nothing onscreen but the drive's pilot or progress light comes on (generally a red or a blue light) and you hear a purring sound of the drive from within, it's not the hard drive that's failed but most probably the SATA to USB component that is attached to the casing. All your valuable data is probably still alive and kicking on the drive itself, it's just that you can't access it in its current condition.
So, how do you fix it in order to access the contents? Well, therein lies the difficult part. The casing needs to be carefully opened but it is not as easy as unscrewing four or six screws and lifting the lid off. This is computer periphery we're talking about here, after all. Nothing is that simple when we need to get inside some computer apparatus to try and fix a problem. But there is a way, as I learnt recently when I had two external hard drives fail on me at the same time.
Yes, they lit up when I plugged them in to the USB socket on my laptop computer; yes, they purred like a ten-week-old kitten who's been hugged and hugged some more by its new owners; yes, maybe the 'safe to remove' USB logo appeared on the 'Show hidden icons' area of the taskbar. But no files or folders appeared on screen in Windows Explorer. That's the time you know things can get a little bit messy.
Warning! Do not attempt the next bit if you still have a valid warranty covering the external drive.
If you are not technically minded or computer repairs literate, I would suggest you either get somebody more competent to perform this operation or you just dive in and hope you don't sod things up even more than they already are. As I said, the drive case needs to be opened. This can be done carefully but firmly by edging a very small, thin screwdriver or even an old credit card around the edge of the seam joint on the case. Most external hard drive cases follow a similar pattern... they are made of plastic and are joined together by plastic poppers housed inside the case.
The trick is to pick a spot along the seam and ease the two edges apart. The case should then start to pop open and you could use an old credit card or store card to replace the screwdriver until the top of the casing separates from the bottom. Inside, you'll see the hard drive, just a normal run-of-the-mill hard drive that you would find inside a laptop. It will be connected to the SATA socket. It needs to be carefully removed from the socket and the casing.
Once free, you can access the data on the hard drive by attaching it to a SATA to USB adapter and attaching that to the computer via the USB socket. Provided the drive itself is not knackered, the content of the external drive should then pop up onscreen and will be fully accessible. The original casing is most likely no longer usable and can be discarded appropriately and responsibly. The drive itself can continue to be used, either by using the SATA adapter, an external drive caddy or even as a replacement or secondary internal hard drive. The choice is yours.
None of us should forget that, if we throw away our external hard drives without trying to retrieve and delete the contents, personal and private information most likely will go with it. And who's to say where that'll land up?
Trevor Mulligan