What you'll notice
Every HDMI input, the tuner and every app show the same blank/black/error state — the fault follows the TV, not the source.
Why it happens
A failed mainboard, or a failed connection between the mainboard and the panel's T-Con board.
How we fix it
We test the panel and T-Con independently to rule those out, then repair or replace the mainboard with the model-correct part.
Still not working?
If the checks above haven't restored your mainboard (logic board), this usually needs a technician. Our TV Mainboard Repair service covers exactly this fault.