After receiving your SSD, the S-ASC(Samsung-Authorized Service Center) will evaluate any damage and authenticate the serial number and the model code to verify that the warranty is valid. After authentication, S-ASC will screen the SSD for any problems. If there is any problem with the returned SSD, S-ASC will replace the drive with another SSD and mail it back to you. If no problems are detected, S-ASC will return the original SSD to you.
For your reference, most returned SSDs have no problems. Please read the install guide and FAQs carefully before you return your product so you are not inconvenienced by an unnecessary return.