Bad news. LCD panel itself. Squeezing the area at the edge confirms this, three options:
Replace panel ($$$).
Buy new better LCD TV (samsung not a problem still. Any makers can get affected by a failing panel anyway and is same technologies in how it is constructed).
Send panel to LCD panel repair to rebond the bad connection of tape circuits (there is several businesses found on google).
Your LCD of this vintage has T-CON board is at top center and is not the problem since this usually cause noise or no picture whole panel itself.
Newer Samsung LCD TVs (starting this late 2008 and 2009) their panels is flipped 180 with T-CON at bottom so LVDS cable is now shorter run and allows T-CON board and Y lines buffers to run cooler).