I have a Samsung LN40a630m1fxza TV. The picture was intermittently coming on when the TV was powered on and now no longer comes on and displays any image. It appears the backlight is working because it is glowing but when you select anything to display on the screen (like menu, input, volume or channel) nothing shows up. I am pretty good with electronics. Are there any test points that I can check to determine if it is a connector, board or LCD?

Thanks
Terry

Re-seat the LVDS cable (that's the ribbon cable between the main board and the TCon). Chances are if you have backlight and sound, but no OSD the culprit is either the LVDS or the TCon. It could still be your main board though.

Also, while you have it open, check the power supply. There should be some capacitors near a heatsink. Check to see if they are bulged, and if so, replace them with some higher voltage capacitors. For example, if they are 10V, replace them with the same capacitance, but using 16 or 25V instead.