my desktop won't recognize my external hard disk

[Vidya]

this has been an issue for some time, so I called a tech. He performed some magic and got my desktop to recognize my external hard disk.

Now once again when I plug in the HD, the computer simply doesn't show it’s connected. I badly want to save my files on the HD. What to do?

I don't think I need to buy a new HD; when I plug it in, the yellow light on it lights up and it makes a low beeping sound, so I assume its working.

[TimothyEllis]

Could be the driver is corrupted. If so, you need to uninstall the driver, and let the device install it again.

The other thing you can try is to plug the device into a different usb port. This forces the installation of the driver again.

One reason this happens is when too many things get swapped on too few usb ports, so eventually the computer gets confused. Adding a bigger usb hub and never swapping devices can often solve this. And if it does happen (computers do lose things), as I said, use a different port to force it to recognise it again.

[Vidya]

Thanks, Tim. I tried to plug the device into a different usb port, but still nothing.

I don't think i’ve ever swapped devices on usb ports.

How do I uninstall the driver and let the device install it again?

[TimothyEllis]

I hate to say it, but you're probably best off googling a how to vid.

[Simon Haynes]

The nuclear option I use is to go into device manager and delete (all) the USB controllers. Then scan for new hardware.

Sometimes the drivers for the USB controllers get corrupted or confused.

I wouldn't recommend this unless you're really desperate, and you know how to fix things if you mess it up. (Difficulty rating 9/10)

[Post-Crisis D]

In situations like this, it might also be helpful to mention OS (Linux, Mac, Windows) and version as different operating systems may have different means of handling such issues.

[Simon Haynes]

Linux is the easiest - just type dmesg in the console and look for a string of USB error messages. (I have an external HD which is flaky, and it spews error messages like a little lost robot.)

[Vidya]

Thanks, everyone. I use Windows.

I am not at all tech savvy and I fear installing new drivers if it’s anything complicated. i’d rather call the tech. i’ll google and see if it’s simple enough for me to handle.

[Vidya]

I googled, went into device manager, uninstalled all the USB controllers, then restarted the computer.

Apparently restarting is supposed to automatically install new drivers and it must have done so with the mouse, but my desktop still won't recognize my external hard disk.

What now?

[TimothyEllis]

Try the HD on another computer. If it doesn't work there either, the drive is dead.

[Post-Crisis D]

Try the HD on another computer. If it doesn't work there either, the drive is dead.

Or the USB controller card for the drive is dead.  If that's the case, installing the drive in a new external box might work.

[Vidya]

Dan, you mean buy a USB hub?

[Post-Crisis D]

Dan, you mean buy a USB hub?

No.  I was thinking something like this:
https://www.amazon.com/gp/product/B00LS31KQG/

The actual model you would need would depend on the size and type of the hard drive.

I don't guarantee that's a solution.  I'm thinking one possibility is that the little card that allows the drive to connect via USB could have gone bad.  It could be the drive itself or it could be that USB controller card.  If it's the controller card, putting the drive in a new enclosure with a new controller card would fix the problem.  But, if it's the drive itself that's the problem, well, obviously that wouldn't fix it.

As Timothy suggested, try the hard drive on another computer.  If it works, then there's some issue (driver, whatever) preventing it from working on your computer.  If it doesn't work, then something is either wrong with the drive or the USB controller card.

The most likely suspect is usually the hard drive though.  But, the USB controller card can't be ruled out.

[Post-Crisis D]

Another possibility is that the connection between the hard drive and the USB controller card inside the case has come loose or broken.

[Demon_Lord]

this has been an issue for some time, so I called a tech. He performed some magic and got my desktop to recognize my external hard disk.

Now once again when I plug in the HD, the computer simply doesn't show it’s connected. I badly want to save my files on the HD. What to do?

I don't think I need to buy a new HD; when I plug it in, the yellow light on it lights up and it makes a low beeping sound, so I assume its working.

Which version of Windows? Windows 7, Windows 10? Can you post the brand and model of the external hard drive please?

Is the hard drive empty? I asked this because there is a feature in Windows that automatically hides all empty hard drives. When I clean install Windows, that is the first thing I modify after selecting a single click.

Here is a video about it
How To Show or Hide Empty Drives in Windows Explorer | Windows 10 Tutorial

[Vidya]

Windows 8

brand and model of the external hard drive:

Seagate
P/N: 9SD2A4-500
S/N: 2GHWV59R

The hard drive can’t be empty. I often saved entire folders to it.

[Demon_Lord]

Vidya, the hard drive might be the issue, because the LED light should be blue, not yellow. It should blink when it's accessing data, and stay solid blue when it's idle.

Try removing the USB 3.0 cable from the drive and inserting it again, it might be loose (this has happened to me). Then try again connecting it to different USB ports. This drive is powered by the USB cable, it doesn't have an extra power source like larger drives do, so it needs an USB port with enough power to move it. And not all the ports in a computer have the same Voltage.  Do this while the computer is on, I mean, don't turn off, or restart the computer before connecting the drive. Then if it still doesn't recognize it, turn the computer off. Wait a few seconds, and with the drive connected turn the computer back on.

I found a video of a guy unboxing a drive like yours, and in it you will see the color of the LED light.

[Guerin]

If this is a spinning hard drive, the problem can be that you're simply not getting enough power to the drive. Most USB drive interfaces really don't deliver enough power and that's why USB adapters made for spinning hard drives will have two USB connectors on the computer end of the connection. That provides twice the power to the drive from your PC. Some will even have external power supplies.

When you plug the drive in, do you hear the PC making sounds? It should when it recognizes a new connection has been made. In Windows 8, right-click on the start button in the lower left-hand corner of your screen and select "Disk Management". Disconnect the USB drive and you should see all the attached drives in your system. Attach the USB drive and see if the Disk Manager now lists the external drive. If it doesn't, I would suspect that the USB interface is not working or there is not enough power for the drive. If it shows the new drive, does it have a drive letter assigned to it? If not, you won't see the external drive in explorer. To assign a drive letter, right-click the drive in the bottom part and assign a drive letter.

[Vidya]

"the problem can be that you're simply not getting enough power to the drive."

so what's the solution to that? what can i add or do?

[Simon Haynes]

Plug it in and very carefully press your ear to the drive. If you can hear/feel it spinning, then that's a good sign. (Don't pick it up and move it around when it's plugged in. Hard drives are extremely delicate.)

Complete silence could indicate low power, or a busted cable/pc usb port/hard drive usb port.

If there are repeated clicks or clacks or other weird noises that's not a good sign at all. Often indicates a failed HD.

[Guerin]

"the problem can be that you're simply not getting enough power to the drive."

so what's the solution to that? what can i add or do?

Is your drive the one shown in the video a few posts back?  I need to know what you are working with to really help. The part number is rather old so I'm not sure what you have. If it is the unit in the video, it should work with normal USB power. Are you connecting directly to the computer's USB port or through a hub or monitor? If connecting through a hub, that could cause a power issue.

Did you do any of the things I suggested you try? Does the computer make sounds when you connect it? Did you check to see if it is listed in the Drive Manager?
 

[Twolane]

I did a quick search on Seagate 9SD2A4-500 and came up with the possibility of a bad cable for your model of drive. Did you try swapping out cables?

Another problem was power to the drive from the USB port. If the port is underpowered, the drive chirps and won't start. There's no reason a USB port should change power, but hey, it's a computer. Who knows?

Another user reported that he held the drive vertical at the same time as he plugged in the cable. Apparently, that started the drive. * shrug *

In any event, if you manage to get it to run even one time, I recommend backing up anything of value you have on that particular drive as fast as you can. Judging by the voodoo magic I read concerning that drive, I would suggest, if/when you get everything copied over, that you not use it any longer. It's not reliable.

[Guerin]