Asus Zenfone 2 Z00AD is Intel Moorefield based Devices.

Case: Zenfone 2 Z00AD hang logo problem, the problem remain exists after flashing
Lets take a look at tutorial how to replace eMMC of Intel Moorfield based device below.

Remove the old eMMC, backup ext_csd, boot 1, boot2, and 256MiB of userarea.

Prepare new blank eMMC, using Samsung KMVTU000LM-B503 (16) BGA153 or you can use Samsung KLMBG for 32GB size, and re-write your previous backup, and resolder the new eMMC to the board. Assemby the phone.

Device should be detected by Windows after connecting to USB port, recognized as Moorefield Device.
The provisioning task in this case (replace eMMC) will be performed twice.
First is to use "ZE551ML_debrick_secure_V2 00_sec_xfstk(New eMMC)", after provisioning device will boot, and shows USB Logo.
Followed by "ZE551ML_debrick_secure sec_xfstk", after finish, device shoud enter Fastboot Mode.

Last Step, Flashing with raw/zip firmware.

Congratulations, you just revive Zenfone 2 Z00AD by downgrading storage to 16 GB 😄
Credit : bagus.dps