Either it's a bad cable or a bad plug

[Alan_47]

Have an external hard drive that may have a bad plug. It could be a bad cable. The computer won't recognize the drive

 

[COLGeek]

Have you tried an alternate cable and/or USB port (assuming this is a USB device)? Can you tell if the drive is powering up (vibration)?

 

[D_Know_WD]

Hi there Alan_47,

You would need to provide some more information as COLGeek suggested.
Is the devices powering up at all?
In case it is, you can go to Disk Management and see how it is recognized over there.

In case it is not, you will need to try different cables/ports. If the issue persists then there should be something wrong with the enclosure. Your safest bet would be to contact a data recovery company, if we assume that the data stored on the drive is crucial.

Some users just take the drive out of the enclosure in similar cases. Keep in mind that this may not work due to various reasons like: proprietary connectors, hardware encryption, etc.

Let us know how this goes,
D_Know_WD