TV turns on but cannot connect to the system and fails to function

Hi TV Experts

Samsung Television UN49KU6500FXZC

Desperately trying to fix my tv. It has been working fine for 3 years. However just recently the it suddenly stopped functioning. When I plug in the power cable ‘SmartTV’ system loads but quickly vanishes. Then the screen remains blank for a few second. Following this the back light turns on, and then it just stops there. When I press any key on the remote, nothing happens, only the remote sensor light flickers. If I try and use the manual joystick controller on the back side of the tv still nothing works. Menu doesn’t show, the volume function doesn’t work, the channel key doesn’t work. Essentially the system just shows blank screen. One thing that still seems to be working is the signal from the RF input (local Antenna) sometime brings one local channel onto screen and that too without any sound. One more device that seems to bring signal to the screen is my kids Nintendo with HDMI cable. The TV projects Nintendo signal onto screen but the screen then seems to have lost true colours and the screen has green ting to it, plus I still don’t get sound. I have copied some pictures of the boards on the back side of the tv. Any help in diagnosis will greatly appreciated. I can upload a video of what happens when I turn the TV on.

Thanks

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