Lg tv led 3times blink only and after that normal position

I thinks you need use a new power board instead of the old power board ,you can have a look https://www.abctay.com ,you may find what you need.

Take the screen off connect power and watch LEDs if any don't flash its LEDs only needed to change faulty strip if they all flash its probably t con boards.

tube will be have the problem

These 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. http://electronicshelponline.blogspot.com/

It sounds like main board fault. These 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. http://electronicshelponline.blogspot.com/
Blinking codes details to many popular brand TVs are given. Surf the site with patience.

Does the screen quickly blink on and then off? Does the standby light slowly blink twice and then go out?If these are the symptoms then it is probably a bad led backlight strip.This was the fault with my lg 47ln540v led lcd tv.I have written this up in a previous post more comprehensively.Hope this helps..

These 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. http://electronicshelponline.blogspot.com/
Blinking codes details to many popular brand TVs are given. Surf the site with patience.
Normally continious flashes of standby LED indicates a main board failure. Anyway, count the number of blinks as stated above, and make sure about the fault. Contact any service technician.

bad circuit board

I have a tv sony lcd klv32bx300 when turning on works for about 15mins then sfhuting down and blinks 3times the red led on standby signal . Then stop for 2sec and again blinks 3times. I bought this tv in the middle east but we are h ere now in phils. I br ought this problem here in sony service center but the cost to repair this problem is half of the price when i bought. Any one can help to fix this problem