Samsung HDTV: needs repair again

This is going to be the third... This time I even managed to shoot it on video camera, how the TV, after just being turned on, would first shut the picture off, 5 seconds later sound goes too, and the infamous "three lights of death" would start blinking. I've a suspicion it has to do with sound subsystem, as it usually occurs when channel is switched, and the new channel is loud all across the sound spectre (such as World Cup transmission). Not sure if I sould take any more repairs or is it time already to demand a new device.