Fire 8 HD 2018 boots into diagnostic mode only

I have been helping a friend to fix his Fire 8 HD 2018.

This device only boots into Diagnostic Mode with a table showing various values. Specifically
FATPSN = Invalid
Abnormal battery status = AUT

See attached image.

Any way out of this problem?

https://drive.google.com/file/d/1wrT31f-xhus-vtIP_BojSLgxv4mH4q41/view?usp=sharing

UPDATE: Problem solved. See Post #10.