LG OLED65B7A-U doesn't turn on, steady red LED then four slow blinks

LG OLED65B7A-U doesn't turn on, steady red LED then four slow blinks

I have been searching online for an LED code reference or service manual without luck. I am hoping this is an easy fix like replacing the power supply board. If you have a link to a service manual or any information such as checking voltages I would really appreciate you sharing it. Thanks.

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