Initially when power is turned on there is a picture and with audio. Then shortly after turning on the screen blacks out leaving only the audio. What can be causing this? Samsung model number : LN 198 360 CSD. Samsung Model Code: LN 198 360 CSD XZA.

can you provide a picture

The set will need to be properly diagnosed to narrow down the problem. You could be looking at a bad inverter, bad CCFL lamp, fault in power supply or main board.

Appear the high voltage don't is generated, may be the power supply internal, normaly is caused by failure the current-down and overload.
Review the voltages of the main source.

Hello.The screen goes black means that the backlights of your LCD is not working.Maybe the problem is the power supply or the driver board of the backlights.They shutdown because there have a shorted parts on the circuit or power supply. Did you try to reset the power and turned on and get a picture or every time that you reset the power it will get a picture and the picture goes black?

If the screen works for a short while and then completely fails once the TV warms up you have a problem with the main unit video board or the LCD control logic board. Most often if the picture cuts out but audio continues to work the logic board is over heating and should be replaced. However if the picture cuts out and audio shuts off as well then its your video input board.

if the display did not lit and power indicator is flashing rapidly------you will have short circuit in speakers cables -----turn it off and remove short circuit cable-------or you have block in ventilation holes---------turn power off and leave it to cool down and remove anything block ventilation holes---and turn it on again after cooling---------another solution-------on screen display is set to off on system setup------turn it to on in system setup.

Hey did you ever get rid of the "racing stripes"?? my P50HDM now has the same problem...i know this is askin for spam but if anyone has the solution email me at [email protected] thanks

this is from a tech tip I got that should help.
No Picture:
1. The Power Supply may not be producing the correct voltages.
2. The Digital Module (Digi-Main) may not be producing correct
turn on commands (Power 1 and 2).
3. The Logic PWB may not be supplying the correct Vs/Va turn on
commands (Vsago and Vcego).
The Panel can have a defect of two natures.
1. The panel is shorted.
2. The panel is defective, but not presenting a short.
3. Y-SUS and/or X-SUS may be defective (Shorted and or nonworking

Sounds like a power supply problem unless there is a short in the deflection circuits causing the power light to flash. I'm afraid it'll take a technican to figure out what is wrong. If it's more than 7 years old, you might consider replacing it.