I was going to make a reply to »
Samsung LCD TV No Picture but has Sound but the topic was too old.
I too have this problem, luckily I just bought it back in August so still very much under warranty.
Samsung sent out a repair tech today but as always seemed hesitant that it wasn't the tv but rather the source of the input (in my case the DirecTv box). Even after I thoroughly explained to him that the bulbs weren't illuminated and I saw no menu on the tv when I tried to change source or anything else.
He ended up replacing the main circuit board, but it wasn't 30 minutes after he left the problem occurred (but yet, never happened once while he was there). So now he's ordered a new panel which will hopefully fix it. If not, I still have a good 10 months on the warranty to get it sorted out, but frustrating nonetheless.