Lacie external hdd

hello,

I have an external Lacie HDD which does not seem to function.
When I plug it into a USB port I can see the HDD in the Computer Management snap in. I have formated it with exFAT. When I try to move something to the HDD it will start off right then will get to a certain %, after a while it will come up with a message saying that it cannot find the hdd.
I have monitored the activity of the flashing blue light & at the start of the transfer it would flash constantly, then slows down till eventually it will go off.

What can I do to get the HDD to function right?

It sounds like a hardware issue. If it's in warranty period I'd return it.

Edit: if you have another open USB port try that. If you know someone with a computer try it plugged into their machine. That should tell you if it's the drive or something on your system.