Those blinks [flashes] are fault indication (Error Codes). From the number of blinks occur at one time switch ON, you can get an idea about the faulty circuit section inside it. This will make repair easy. These are called blinking codes. Make sure about the exact number of blinking of the standby/power LED, by switching On & OFF the set, for at least two times. Count it carefully. If you wish to get some details, check the site linked here. It has details about blinking codes, and fault locating procedure, to many popular brand TVs and other devices.
If blinks continue without any pause, the main board is faulty.
Search the site by type in the "brand name"
to your device, [Exclude the model number]
in the "Search box at the top right of the display window of the Homepage
" to get gathered related posts. 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 above. Pull up older posts.
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.