I have a Samsung 4500 series plasma tv. Suddenly today the picture only displays in the upper left corner of the tv. its not due to the aspect ratio or zoom. What is causing this?

That's weird. If your remote has a "live TV" button, try pressing that. If not, all I can tell you is that the problem is in the aspect selection.

this is an aspect ratio problem ans is corrected /adjusted on the on screen menu
use the remote to achieve the on screen menu and scroll around until you find aspect ratio
use the volume buttons to select and adjust

flash O.S.Update

On your original TV remote look for button that says Picture size, Format or Ratio and press it till you see the normal size.

It seems that the width of the displayed picture is less than normal. Change the aspect ratio to 4:3, and check. Go to picture setting menu to adjust the aspect ratio. Check its user manual for more details.

Hi, the aspect ratio is set incorrectly for the source material or the screen is simply set to 4:3 aspect (old TV size) manually. There will be a menu function or an aspect button on the remote for doing this. Set it to auto which is usually good enough for most viewing though the ratio may change during adverts and back again for the film on tv watching. This can be annoying so when on tv mode observe the ratio set when the film is on and manually set this ratio, usually 16:9. The display will normally tell you the ratio setting at the point of change so you can do this. I hope this helps.

Steve at Olive Country Computers in Spain

The people look fat and stubby is due to trying to display pictures that were made for old TV 4:3 aspect ratio and you are now trying to fill in the TV screen that has 16:9 aspect ratio. The only way for you to see proper pictures is to set the aspect ratio to 4:3 mode or set it to automatic to let the TV select correct aspect ratio of the pictures, the bad part is that you will see black bars on the left and on the right of the pictures, see more details with regarding to the aspect ratio in the user manual.
Learn more here also:
http://hometheater.about.com/od/televisionbasics/a/aahdtvfaqs6a.htm

http://reviews.cnet.com/16:9-widescreen-tv-aspect-ratio/

Not sure about your sound problem.

That is because you are trying to display the 4:3 old standard TV source to fill in the 16:9 screen. If you want to watch it with correct aspect rarion, you will need to use the 'ASPECT', 'PICTURE MODE', or 'WIDE' btton on the remote to change it.
Most people does like to see black bars on the left and the right sides of the picture when view in 4:3 mode so they stretch the picture to fill the screen, and that is what you will get, people will look short and wide.
Please see your owner manual that will explain the aspect ratio of the pictures in various modes.

http://www.fixya.com/support/r5093881-lcd_flat_panel_tv_troubleshooting_guide
http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting
Failed TV and Monitors: http://s807.photobucket.com/albums/yy352/budm

try to check the aspect ratio and input source to make sure they are correct. for the aspect ratio, make sure it is set either at 16:9 ratio or try the zoom options. if it is set at zoom, you can move the screen left to right or up or down through the zoom settings. make sure you are also using the correct cable. hope this helps

There is an aspect ratio setting in your menu options. You will have to change the aspect ratio so you get a normal screen.
This will most likely fix your problem.
If by slight chance it doesn't, you will have to remove the back of the tv and find the manuyal adjustments for it.
All newer Tv's have the aspect ratio/picture change setting.