I wonder if your T.V. has been stuck in demo mode?
There are 2 ways to take your tv out of demo mode.
The first way is going to take you through a Plug & Play
Turn on the TV. Change the source to the "TV" source. Press the menu
button on the Samsung Remote. [The Main Menu will appear] Use the ▲ or
▼ arrows to navigate to the "System" or "Setup" menu (Depending on the
model of your television), and then press ENTER. [The System/Setup
menu will appear] With the ▲ or ▼ arrow buttons, highlight "Plug &
Play". Press ENTER. [The Plug & Play menu will appear] When the
message, "Menu language, store demo, and time will be set", press
ENTER. Select your menu language, and then press ENTER. Highlight and
select "Home Use". and then press ENTER. If you are not using the
internal tuner on the TV, you can skip the rest of the Plug & Play, as
the Auto-program or the time is un-needed. The second way is more
difficult, but it is useful if you do not have a samsung remote.
Note: The timing needs to be correct, or this method will be
ineffective.
With the TV powered on locate the buttons on the panel, on most TVs
they will be on the bottom right corner of the screen. After you've
located the Volume - and Menu buttons, we will press them in a certain
combinaton. Press the Volume - button once. [The Volume indicator will
appear] While the Volume indicator is on the screen, Press and hold
the Menu button for 10-15 seconds. If done correctly, the screen will
say either "Store Demo" or "Standard" (or "Dynamic" depending on your
model). If the TV says "Store Demo", repeat steps 2 through 5 to take
the TV out of "Demo" mode. When the TV says "Standard" (or "Dynamic
depending on your model) your TV is no longer in demo mode.