If you can see it in your computer then it is working. Make a note of the drive letter assigned to it and copy files to the new(secondhand) drive.
If they copy ok then you can be sure that it is ok at that time. I don't know of any way of checking that it will still be ok next year, next week or even tomorrow, but that is the same for any drive in your computer (thats why backups are so important).
You could try leaving the computer on for a few hours to make sure that the new drive is ok when it has been running for a while and has heated up.