Not recognizable to Macbook and can't get my data off

When I plug my external into my computer by the USB, it goes unrecognizeable. The light blinks but I cannot get any data off.  I tried a different USB adapter and the connection is STILL lost.  help!

Hello,

I recommend you try some basic troubleshooting

1- Connect the power adapter to the wall directly.

2- If the computer is a desktop, connect it on the back USB port (directly to the PC, not through a hub).

3- Go to disk utility, and verify if the drive shows.

-If it shows in disk utility then click on verify disk.