Hard disk refurbishment, now basically no, before the expensive time is more, now are fake, for example, replace the hard disk sticker, this in the Western Digital hard disk is more, Western Digital model and price is too much.
To see if it has been used, usually use the software HDTUNE, there are other hard disk testing software to check.
How to identify, the motherboard look at the reverse side of the soldering pins, the original are machine welding, so the solder joints are very regular, and very neat, refurbished hand soldering, workmanship is very rough, and look at the motherboard capacitors are the same brand, the PCIE or PCI sockets inside whether there are scuff marks, whether there is indentation of the base of the CPU (heatsink).
Hard disk visual inspection, see whether the screw holes have scratches, hard disk paste is 2 layers, it is best to use the serial code on the paste to the manufacturer's official website to check whether the interface part of the solder joints are abnormal.