I have no picture, only sound.

@max82116 it's a Philips (known to have bad backlights) and the symptoms you describe sound like abad backlight array.

A simple check for that would be to darken the room and turn the TV on. Then use a flashlight and shine the beam at an angle against the screen. See if you can make out shadows or shapes. If you do, then it is your backlight that has failed. If you do not see anything, unplug your set and remove the back cover. Then visually check the boards for any obvious damaged components. Check all the wiring and unplug the wires and plug them back in, make sure they are properly seated. It is possible that this is either a power board or a T-con board issue.