We're sad to hear of the issue you're having with your TV. We would strongly advise against trying to repair your TV yourself however. Would you please run a Picture Test on the TV to see if the issue shows there? Go to Home > Settings > Support > Self Diagnosis > Start Picture Test > OK.
@Narutogon: If you click on the word 'here' in the post above by @ChrisM then this contains a hyperlink to the Service Locator feature of our website. For visibility, I have gone ahead and added the link below.