It will be difficult for you to fix it yourself - a TV doctor might be able to fix it for you.
It has a warm-up fault - very probably in the power supply - a component works for a while but as it begins to heat up it quickly fails.
Confidence - experience - test equipment and circuit diagrams will be needed. Else a can of freezer spray to selectively cool individual components.
You do not mention the make or model but no matter.
Good Luck..., April 2017
