When picture come on tv scree it atomaticaly switch off

Check and replace damaged component/s at its horizontal scan output section circuit. Check the LOT (Line Output Transformer) too for damage. Replace the horizontal scan output transistor. Check the input voltage to LOT. If the voltage is absent check the feeder resistor; if any. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/ Type in this key phrase " my service table today " in the search box at the top right of the the home page, to get gathered some pages which has the details of practical experiences of the author of that site. The search result might display about 20 Nos of related posts. Press the "All posts" at the bottom of the list, then you can select them one by one.