If an item is under warranty surely they should atleast look at it then decide on the fault. A diagnosis cannot be established without witnessing the fault first hand. Id argue the case and suggest they they take the tv to investigate the fault. Thats the least they should do. If they do discover water/fluid ingress then so be it. But if they find something else to be wrong they can fix it under warranty
Our 55 inch LG smart 3d TV developed a vertical strip about 150mm wide from top to bottom whilst still in the warranty period. their response was to say it was due to corrosion from either having chemicals sprayed on the screen or moisture from a nearby aircon unit their third possibility was my partner spilled a drink on it. as non of these were fact i appealed to them on the basis of the quantity of LG products we have, 9 in total. Result was no claim. i am using this forum to warn anyone who is interested to be cautious as warranty is all in the interpretation and unknowing consumers are often at the mercy of the big manufacturers

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