The information required to decrypt the TPM key can be backed up in USB memory, taking into account cases such as when the TPM chip needs to be replaced.
Insert a USB memory device into the USB port of the machine.
Tap [Utility] - [Administrator Settings] - [Security Settings] - [TPM Setting] - [TPM Key Backup].
Tap [Restoration Password], then enter the password to decrypt the TPM key (using between 12 and 64 ASCII characters).
Tap [Start].
The TPM key is saved in USB memory.
Do not remove the USB memory device during the backup process.