• The Adapter card into the computer's solid-state hard disk socket insertion is not in place, you can use a little force.
• The hard disk is used incorrectly. Some buyers will install M2NGFF hard disk based on 5ATA protocol, so it will not work.
• The installation disk of the system must be 10.13,6 version or higher.
• The partition format of hard disk is not correct. It is not recognized when installing the system. It must be GPT (GUID) partition format. Be careful not to use any Windows partitioning software to partition the hard disk into PE system, otherwise it will bring numbness to the later installation work.
• Do not install the system from the network, nor try to restore the system with your original backup, because the old and new versions of the for Apple system disk format is not the same.