Panasonic tx-l42e5b

[moosemaurice]

I've got one that recently was switching on but no sound or picture until reset, now won't come on at all. I've checked the power supply and all voltages seem OK even stripped the screen and checked the leds individually and all lighting up OK. It's not showing any fault codes, is it possible that it's needing firmware update or is it likely to be the main av panel that's faulty? Any advice or help would be greatly appreciated thanks.