Multiple symptoms: entire backlight off or partial gray area
TV: LG 55GA7900
My TV shows multiple symptoms.
When it shows problem, few seconds after turn on the TV, either 1/10 of screen shows shadow (LCD still shows image) that looks like partial backlight out or entire backlight goes off (Still I can see lcd is working when I put flashlight).
On the other hand, the TV works just fine sometimes for as long as it gets when it doesn’t show the problem.
I initially thought this could be a power supply board issue because all led bulbs seem to work just fine when the TV works fine.
So I was going to replace the power supply board but I also read an article saying that some TV shuts off when there is bad led bulbs in the back light.
I need help to isolate the problem whether the power supply board is wrong or there is a bad led and here are my questions.
- When the TV shuts down to protect it from bad led bulbs, is it just turn the back light off or turn entire TV off?
- Can defective led strip be working fine for hours, partially out, or out entirely and the symptom randomly repeats?
Thank you in advance for all of your answers.