Philips FTR9966/17S receiver box broken - black screen, but sound

We recently hooked a new soundbar up to our 4 year old Philips FTR9966/17S Plasma TV. It worked fine for a day, and the next day we got a black screen, and the red light on the TV would blink. Yet, we could still hear sound through the soundbar, and it sounded like the TV was channel surfing. Weird. We called Philips and they referred us to a repair guy, who took the TV home with him. He brought it back a week later, and it worked for about 5 minutes, then the same problem. So he took it back with him again, and now he's saying that the receiver box is broken, and that Philips doesn't make them anymore. Therefore our 3K TV is shot. Is it true? could that be? Would the TV not work without the receiver box, isn't there a way to hook the TV up directly to the cable line? Anything you think we should try to fix this?
Thanks, Brad and Michaela