This TV had backlight and sound but no picture.  A badcaps thread indicated a common problem was a blown fuse on the Tcon board.  On my TV, I found 3 bulged 1000uF/25V capacitors on the power supply and the blown fuse.   The Tcon was difficult to access because there was a shield and part of the frame blocking it.  I had to peel back the foil tape to expose and unlock the ribbon cables and unscrew part of the frame so I could slide the Tcon board out.  The P marking on the 0603 fuse indicated it was 3A and I replaced it with a 1206 3A fuse from a scrapped Tcon board.  With the parts replaced, the TV powered up with no issues.

Other model numbers LN-S4692D LNS4692DX/XAA