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I have an LG 55LA7400 UD. last night after watching for 4 hour we changed the channel and discovered a dark streak about 6” wide at the top and a foot at the bottom. How much would it cost to get it fixed at a tv repair shop ? baebler73@gmail.com
Could you post a picture of it. Sounds like the panel is damaged, if so there is no fixing it only option is to replace the television.