MY Hvx 200 Is totally Black when I turn it on. the display and playback of my old footage works fine but the picture is totally black. any Ideas When I switch the camera on, the view finder is totally black.  Playback of previous stuff works fine.  I think I may have accidentally changed a setting somehow.

Did you switch to Tv (shutter mode) and took pictures for several seconds? like in the dark? Because saving the picture can take as long as the shutter time was.
Before panic. (Actually you never should panic) check your camera in automatic mode. And make sure you did not select any power save action, that puts your display on dark while shooting.
But always be sure your battery is charged and check its capacity. In the menu yo can check under the wrench symbol, when you select Battery info. Page 268 of the manual.
Working with a bad battery can damage the camera in the end.

Think that you might have accidentally pressed the DISP or DISPLAY button on the back of your camera. This manually turns the LCD display on and off to save batteries. You would then use the optical viewfinder in its place. To turn the screen back on, just press the DISP button one more time.

if you can playback good old recorded tapes fine. you can record audio but no video ? this is the ccd. samsung is known for this in alot of there products ...did it get dropped or bumped really hard ?

Turns out my husband must have pressed a button by accident. The bottom left button says "disp" for display. Pressing that fixed the screen!

THIS MEANS THAT CAMERA PART HAS A PROBLEM BUT NOT THE PLAYBACK PART.MUST BE A CAMERA BOARD PROBLEM THEN.OR EVEN POWER SUPPLY PROBLEM/ VOLTAGE FEEDING THE CAMERA BOARD FOR EXAMPLE.

the display of ur laptop has got damaged....if u still have doubt that it might be some software problem try formatting ur system.. Or else u should go for a change of display screen

See this link

If you take a picture using the optical viewfinder, does the camera actually record the picture? If so, you may have the LCD turned off in the camera mode (there are three options: standard, detailed, and off). With the camera in the shooting mode, press the "DISP" button and see if the LCD turns on.

Intermittent fault? Playback of recorded footage not possible.
Even tried to check 'playback' with an older tape.

If you can display pictures in playback mode but screen is black in capture mode then the CCD sensor has stopped working and needs replacing.