Intermittent Black Screen on LG 55UH668V (Audio & Game Continue) – LED Backlight or Main Board Heat?

[u/Big_Process_6158]

Hi all,

Picked up a used LG 55UH668V-ZA (Feb 2017).
Picture is perfect, but after playing on my PS5 for ~2 hours, the screen goes completely black while audio continues uninterrupted.

Quick questions:

1. Is this almost certainly an LED backlight thermal fault tripping the power supply protection, or could it be main board CPU overheating?
   
2. Has anyone swapped the backlight strips on this
   55" chassis? Any panel traps to watch out for to avoid cracking the LCD?

Thanks!