Solved! 50L711U18 toshiba question

[Cuddlyfriction]

What may be causing this? Default settings tv shuts off after about 30 seconds but still outputs sound... if I turn the backlight down in options the tv might last 5 extra minutes but still turns off still outputting sound

Edit: already opened tv brushed air vents and vacuumed inside

 

[helpstar]

have a look at https://www.shopjimmy.com/toshiba/50l711u18
Might be a faulty main or power board

 

[Cuddlyfriction]

I have a toshiba 50L711U18 my problem is after about 30 seconds my backlights turn off I have done the flashlight test and I can still see the menu and hear sound ... turning the blacklight down in the menu increases the amount of time before the backlight turns off

My next question would be is the auto off feature in the power board or the led strips? Since my tcon and main are functioning

 

[helpstar]

So the backlight is the problem, should be this one:
https://www.shopjimmy.com/toshiba-pk101w1530i-power-supply-led-board-for-50l711u18.htm