WHY DO I HAVE SOUND BUT NO PICTURE?

SOURCE: Half Screen went black

Try to replace the Logic board.

SOURCE: no picture but has sound

your bulb has burnt out

SOURCE: Samsung Plasma 42" TV - 2006

Hi, this is quite a common problem for plasma screens and LCD screens. The fluroscent backlight is more than likely faulty and would need replacing. The best thing to do is to take it to a service centre because there are no user servicable parts inside the plasma.

SOURCE: Samsung LN-S4041DX 40 in LCD TV

Hi. You can try to go into service mode and reset the LCDTV to Factory Default. This will clear out all buffer over run's and any software related issues. It may fix the problem or it may not. If this doesnt fix the problem than you need to have a qualified Technician to look at it. The problem is in the AV circuit board, a technician who is qualified to repair electronics at circuit board level should be able to repair this problem rather quickly and inexpensively. Most technicians who do not have the expertise in repairing cicuit boards to component level would rather replace the whole AV board than repair it and this will be rather expensive.So talk to the repair shop before you drop the TV off.

Be very careful when accessing service mode. I suggest to write down all information in all areas before proceeding to a factory reset. If you do not record all values correclty you run the chance of not being able to use the TV again. To go into Factory Service mode, use the original remote and in this sequence push POWER OFF-MUTE-1-8-2-Power ON, the set will turn on and enter service mode, if you hit all previous keys correctly. If it doesnt try again. When you are done hit POWER OFF and this will exit service mode and save the data.

SOURCE: sound yes, but no picture on tv

If you have sound on the stations this is a problem in the display. Take bright flashlight and hold it against the screen. Look for an image around the edge of the flashlight. If you see an image then it's one of three problems;
1) The inverter board is bad.
2) The CCFT (cold cathode fluoresent light) are bad.
3) The power supply to the inverter board is bad.
Someone knowledgeable in electronics can replace the bad part(s).