LG LH3000 screen issue

[1888bhoy]

Hi guys, i have an LH3000 42"lcd tv, about 18 months old, and recently in the past few weeks i''ve had about a 6 inch light block from top to bottom of the screen on the left hand side looking at it, it eventually goes after 20-30 minutes but can also give horizontal flickering occasionally,

i called LG, but it only came with a 1 year warranty, and was wondering if anyone knew what could be causing this, and if i would be cheaper getting it repaired or just buying new,

thanks in advance,
Stephen