Hi, try this, press 'input' and 'volume -' on the TV button panel and hold down, then power the set on. If it powers on you should see a 'K' on the screen, press vol- and prog + and you will enter the service mode. scroll through it and reset the backlight error to 0, then power down and restart. Hopefully it will come on as normal. It may be that you have a faulty backlight tube, so try that first.