You will need to take it apart and provide photos of the Boards inside.
Take one of the overall set up then one of each side of each board.You will also need to have a soldering iron and multimeter and be able to use them.
Have you had the set some time and it has stopped working or have you just got it?
It looks similar to one I have seen and the TV section is plug in module.
Have you just tried it with the TV aerial or have you tried other inputs into the box
video, svideo. composite?
If it is a box take it out clean up the contacts, replace and try.
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