SamyGO

New mainboard means new flash,cpu,ram,usb,HDMI and other sockets. So you get it replaced and get completelly new tv

I do not understand your flashlight problem, if it is defective, tell to Serviceman and you get it fixed (replaced too) . Tv is like Lego toy - if broken - that part is replaced by new one. That's all

the issue is due to the thinness of the display panel, its very fragile and susceptible to being warped during shipping and/or handling from the manufacturing plant to the dealer and then to the consumer.