Wellington 43FHD279SW TV turns off

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Hi guys, I have a problem with my Wellington TV - 43FHD279SW

power board: 17IPS12
main board: 17MB110S

When summer comes and weather goes hot my TV shuts down after 20-30 minutes work. I changed PB, but it doesn't solve my problem. So I put homework fan on the back of TV & problem has been solved, but it's uncomfortable for me all these cables and PSU around the TV. I'm looking for some advices which of componens pre-heats and better solving for my problem.

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Now just find the problem with pre-heat of chip U95 - ARM MSD 93X3PK2-4-0036 on the MB